American Tower (AMT) 10-K risk factor changes: FY2025 vs FY2024

- technological changes, including artificial [removed: intelligence,] [added: intelligence (“AI”), wireless equipment changes,] satellite technology and an increase in the use of radio access network (“RAN”) sharing among wireless service providers;

One or more of our customers, or their parent companies, may experience financial difficulties, file for [removed: bankruptcy or] [added: bankruptcy,] reduce or terminate [added: their] operations [added: or exit certain markets] as a result of a prolonged economic downturn, economic difficulties (such as those from the imposition of [added: taxes, fees (including the cost of, and access to, spectrum), regulations or judicial interpretations of regulations, and any associated penalties or interest, which may be substantial) or otherwise.]

[removed: The current inflationary and high] [added: Impacts on the economic environment, such as inflation or rising] interest [removed: rate environment] [added: rates,] could materially and adversely affect our customers through disruptions of, among other things, their ability to procure their equipment through their supply chains, their ability to procure power and fuel and their ability to maintain liquidity and deploy network capital, with potential decreases in consumer spending contributing to liquidity risks.

In addition, many of our customers and potential customers rely on capital raising activities to fund their operations and capital expenditures, which may be more difficult or expensive in the event of downturns in the economy or disruptions in the financial and credit markets, [removed: such as the current environment driven by the significant challenges] [added: including those] caused by factors such as inflation, currency devaluations and other foreign currency exchange rate volatility, higher interest rates and supply chain disruptions.

If our customers or potential customers are unable to raise adequate capital to fund their business plans or face capital constraints, they may reduce their spending, file for [removed: bankruptcy or] [added: bankruptcy,] reduce or terminate [removed: operations,] [added: their operations or exit certain markets,] which could materially and adversely affect demand for our communications infrastructure and our services business.

In the ordinary course of our business, we [removed: do] occasionally experience disputes with our customers, generally regarding the interpretation of terms in our leases.

However, it is possible that such disputes could lead to a termination of [removed: our] leases with those customers, a material adverse modification of the terms of those leases or a deterioration in our relationships with those customers that leads to a failure to obtain new business [removed: from] [added: or maintain existing business with] them, any of which could have a material adverse effect on our business, results of operations or financial condition.

If our customers consolidate their operations, exit their businesses or share site infrastructure to a significant degree, our [removed: growth, revenue] [added: growth] and [removed: ability to generate positive cash flows] [added: revenue] could be materially and adversely affected.

[added: We may not be able to renew existing customer leases] or enter into new [added: customer] leases, [added: or if we are able to renew or enter into new leases,] they may be at rates lower than our current rates or on less favorable terms than our current terms, resulting in an adverse impact on our results of operations and growth rate.

In addition, some of our data center competitors [added: may] have significant advantages over us, including greater name recognition, longer operating histories, lower operating costs, lower levels of leverage, pre-existing relationships with current or potential customers, greater financial, marketing and other resources, access to better networks and access to less expensive power.

Similarly, our data center site infrastructure may become antiquated [added: or obsolete] due to the development of new systems that deliver power to, or eliminate heat from, the servers and other customer equipment that we house or due to the development of new technology, such as [removed: artificial intelligence,] [added: AI,] which is potentially more power-intensive, that requires levels of power and cooling density that our facilities may not be designed to provide.

[removed: Conversely, we may invest significant capital in technologies, platform expansion initiatives or new additions to our core] business that may not provide expected returns or profitability, which could divert management attention and have a material adverse effect on our operating results.

Divestitures [removed: and strategic partnerships] may materially and adversely affect our financial condition, results of operations or cash flows.

Divestitures involve risks, including difficulties in the separation of operations, services, products and [removed: personnel or] [added: personnel,] requirements to obtain consents from third [removed: parties.][added: parties or potential legal claims or regulatory requirements.]

We cannot assure you that we will be successful in managing these or any [added: other significant risks that we may encounter related to the divestiture of a business.]

[removed: Furthermore, as] [added: As] we continue to engage in [added: and sustain] partnership [removed: opportunities to support our expansion initiatives,] [added: opportunities,] our partners may have business or economic goals that are inconsistent or conflict with ours, be in positions to take action contrary to our interests, policies or objectives, have competing interests in our, or other, markets that could create conflict of interest issues, withhold consents contrary to our requests or become unable or unwilling to fulfill their commitments, any of which could present challenges with multiple partners or expose us to additional liabilities or costs, including requiring us to assume and fulfill the obligations of that partnership or to execute buyouts of our partners’ interests.

Our [removed: leverage and] [added: leverage,] debt service [removed: obligations, including during a high interest rates environment,] [added: obligations and repurchase activity] may materially and adversely affect our ability to raise additional financing to fund capital expenditures, future growth and expansion initiatives and may reduce funds available to satisfy our distribution requirements.

- impairing our ability to meet one or more of the financial ratio covenants contained in our debt agreements or to generate cash sufficient to pay interest or principal due under those agreements, which could result in an acceleration of some or all of our outstanding debt and the loss of the towers securing such [removed: debt] [added: debt, as applicable,] if a default remains uncured;

Further, market volatility and disruption caused by factors such as [removed: inflation, higher] [added: inflation and fluctuating] interest rates [removed: and supply chain disruptions] may impact our ability to raise additional capital through debt and equity financing activities or our ability to repay or refinance maturing liabilities, or impact the terms of any new obligations, which in turn may have an adverse impact on our credit ratings.

Federal fund rates have been elevated for several years and, although there were several rate cuts in [removed: 2024,] [added: recent years,] rates could remain at current [removed: elevated] levels for an extended period of time.

[removed: Such elevated] [added: An increase in] rates [added: can] have a corresponding impact to our costs of borrowing and may have an adverse impact on our ability to raise funds through the offering of our securities or through the issuance of debt due to higher debt capital costs, diminished credit availability [removed: and] [added: or] less favorable equity markets.

The extent to which these factors will impact our business and financial results will depend on future developments, which are highly uncertain and cannot be predicted at this [removed: time due to the rapid evolution of this uncertain situation.][added: time.]

[removed: High] [added: Increased] inflation [added: and interest rates] may adversely affect us by increasing costs beyond what we can recover through price increases.

[removed: Current and future] [added: Future] inflationary effects may be driven by, among other things, supply chain disruptions, changes in trade [added: or tariff] policies, governmental stimulus or fiscal policies, as well as ongoing global military conflicts.

[added: In addition, should] inflation rates exceed our fixed escalator percentages in markets where our leases include fixed escalators, our returns could be adversely affected.

In an inflationary environment, [removed: such as the current economic environment,] depending on the terms of our contracts and other economic conditions, we may be unable to raise prices enough to keep up with the rate of inflation or our customers may be unwilling to pay contractual increases or demand discounts upon renewal, which would reduce our profit margins and returns.

[removed: The ongoing impact of inflation may continue to] [added: Inflation impacts could also] create foreign exchange rate instability in our international markets, including in markets such as Africa and Latin America, that could, in turn, depress the value of that market’s currency, thereby adversely impacting our business, results of operations, financial condition or the underlying value of foreign subsidiaries.

Restrictive covenants in the agreements related to our securitization [removed: transactions,] [added: transaction,] our credit facilities and our debt securities could materially and adversely affect our business by limiting flexibility, and we may be prohibited from paying dividends on our common stock, which may jeopardize our qualification for taxation as a REIT.

The agreements related to our [removed: securitization transactions] [added: Trust Securitization (as defined below)] include operating covenants and other restrictions customary for loans subject to rated securitizations.

[removed: If the borrowers were to] default on any of the loans, the servicer on such loan could seek to foreclose upon or otherwise convert the ownership of the secured assets, in which case we could lose such assets and the cash flow associated with such assets.

We also [added: may] enter into hedges for certain debt instruments, which may have an adverse impact on our results to the extent that the counterparties do not perform as expected at the inception of each hedge.

- uncertain, inconsistent or changing laws, regulations, rulings or methodologies impacting our existing and anticipated international operations, fees or other requirements directed specifically at the ownership and operation of [added: communications infrastructure or our international acquisitions, any of which laws, fees or requirements may be applied retroactively or with significant delay;]

- failure [added: or inability] to retain our tax status or to obtain an expected tax status for which we have applied;

- significant increases in, or implementation of new, license surcharges [added: and similar fees or taxes] on our revenue;

- anti-American sentiment or adverse impacts from United States trade or foreign [removed: policy;][added: policy, including the impacts of tariffs and retaliatory measures;]

We also face risks associated with changes in foreign currency exchange rates, including those arising from the impacts of [removed: the current] [added: an] inflationary and high interest rate environment on the global [added: or regional] economy and markets and [removed: those arising from] [added: on] our operations, investments and financing transactions related to our international business.

[removed: Volatility in foreign currency exchange rates can] also affect our ability to plan, forecast and budget for our international operations and expansion efforts.

Noncompliance could result in the imposition of fines or an award of damages to litigants or result in decreased [removed: revenue.][added: revenue or the potential loss of our sites.]

[removed: Due to the] [added: The] evolving nature of global tax laws and regulations and compliance [removed: approaches, it is currently not possible to assess the ultimate impact of these actions on our financial statements, but these actions] [added: approaches] could have an impact on our financial results.

In addition, as of January 1, 2024, we and our subsidiaries, in principle, [removed: would be] [added: became] subject to the Organization for Economic Cooperation and Development [removed: (OECD)] [added: (the “OECD”)] Global Anti-Base Erosion Rules [removed: (more commonly referred to as the] [added: (the] “Pillar 2 Rules”) as [added: promulgated by jurisdictions.]

Our business, results of operations and financial condition could be negatively impacted by disputes with our customers.

For example, we are currently engaged in a legal dispute (the “Arbitration”) with one of our customers in Mexico, AT&T Comunicaciones Digitales, S. de R.L. de C.V. and related entities (collectively, “AT&T Mexico”).

AT&T Mexico, which represented approximately $300 million of tenant revenue in 2025, is challenging the calculation of the monthly lease amount established under our Master Lease Agreement with AT&T Mexico (the “MLA”), as well as certain other provisions of the MLA, seeking rent abatement both retroactively and prospectively, and withheld certain tower rents during 2025.

As previously discussed, on September 23, 2025, we and AT&T Mexico reached an agreement pursuant to which AT&T Mexico has remitted payment of the majority of the withheld tower rents and has resumed monthly payments of the majority of its owed tower rents.

The remainder of the outstanding receivables and the future monthly unpaid tower rent amounts are being deposited into an irrevocable escrow account, overseen by an independent trustee, to be released in accordance with a final ruling in the Arbitration or by mutual consent of us and AT&T Mexico.

We incurred approximately $30 million of reserves during the year ended December 31, 2025 related to this customer.

We expect to record future reserves until the Arbitration is settled.

Additionally, on September 24, 2025, one of our U.S. customers, DISH Wireless L.L.C., a subsidiary of DISH Network Corporation (“DISH”), delivered a notice purporting to be excused from its contractual obligations under our Strategic Collocation Agreement entered into in March 2021 (the “SCA”).

DISH has failed to meet its payment obligations, and as of January 2026 is in default under the SCA.

We filed a complaint seeking a declaratory judgment that DISH has not been excused from its obligations under the SCA, that the SCA remains in full force and effect, and that DISH remains required to perform all of its obligations under the SCA.

This matter is still pending.

The outcomes of these matters are uncertain, and there can be no assurance that our positions will be upheld.

Adverse rulings in one or both of these disputes could have a material negative impact on our results of operations and financial condition.

The following is a list of significant customers (representing at least 10% of revenue in any of the last three years) and the percentage of our total revenues for the specified time periods received from these customers:

| | | | | | | | | | | | | | | | | | |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| | | | For the year ended December 31, | | | | | | | | | | | | | | |

| | | | 2025 | | | | | | 2024 | | | | | | 2023 | | |

| T-Mobile | | | 18 | | % | | | | 19 | | % | | | | 19 | | % |

| AT&T | | | 17 | | % | | | | 18 | | % | | | | 18 | | % |

| Verizon Wireless | | | 14 | | % | | | | 13 | | % | | | | 14 | | % |

| Telefónica | | | 10 | | % | | | | 10 | | % | | | | 10 | | % |

For example, during the second half of 2025, Echostar Corporation, parent company to DISH, announced agreements to sell a material amount of spectrum licenses, and subsequently began to abandon and decommission deployment of portions of its 5G VoNR and broadband network.

DISH represented approximately 2% and 4% of our total annual property revenue and total annual U.S. & Canada property revenue, respectively, for 2025.

During the year ended December 31, 2025, churn was approximately 2% of our tenant billings.

An increase in our future churn rate resulting from non-renewal, or renegotiations at less favorable terms than our current rates, from one or more of our larger customers could materially and adversely impact our growth rate and revenue.

Conversely, we may invest significant capital in technologies, platform expansion initiatives or new additions to our core

In recent years, we have divested our Mexico fiber and Poland businesses in 2023, our Australia, India and New Zealand businesses in 2024 and our South Africa fiber business in 2025.

Our use of joint ventures and strategic partnerships may expose us to risks associated with jointly owned investments.

We currently operate parts of our business through joint ventures with third party partners that we believe will complement or augment our existing business.

For example, we have joint ventures in our Europe property segment, Data Center property segment and Africa & APAC property segment.

Additionally, we may not realize any of the anticipated benefits of our joint ventures.

Such investments and any future strategic partnerships and/or joint ventures subject us and the companies we manage to risks and uncertainties not otherwise present with other methods of investment.

We have a substantial amount of indebtedness.

As of December 31, 2025, we had approximately $37.2 billion of consolidated debt and the ability to borrow additional aggregate amounts of approximately $9.6 billion under our $6.0 billion senior unsecured multicurrency revolving credit facility, as amended and restated in December 2021, as further amended (the “2021 Multicurrency Credit Facility”) and our $4.0 billion senior unsecured revolving credit facility, as amended and restated in December 2021, as further amended (the “2021 Credit Facility”), net of approximately $36.8 million of outstanding undrawn letters of credit.

Additionally, our Board has approved a share repurchase program allowing us to repurchase common stock through various methods, including open market purchases.

The program does not require any specific amount or number of shares to be repurchased, and management will determine timing and volume based on market conditions and other factors.

Repurchases could impact stock price, liquidity and cash reserves, potentially affecting future growth opportunities.

While intended to enhance long-term shareholder value, there is no guarantee of success, and short-term price fluctuations could reduce the program’s effectiveness.

Additionally, our share repurchase program could diminish our available cash, which may impact our ability to finance future growth and pursue possible future strategic opportunities and acquisitions.

taxes, fees (including the cost of, and access to, spectrum), regulations or judicial interpretations of regulations, and any associated penalties or interest, which may be substantial) or otherwise.

For example, see our discussion of churn as a result of the T-Mobile MLA in our U.S. & Canada property segment in Item 7 of this Annual Report, under the caption “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Executive Overview.”

We may not be able to renew existing customer leases or enter into new customer leases, or if we are able to renew

During the year ended December 31, 2024, we divested from operations in several markets, including India, Australia and New Zealand.

other significant risks that we may encounter related to the divestiture of a business.

In addition, should

Although the Federal Reserve Board and other central banks began cutting interest rates in the latter part of 2024, interest rates remain above recent norms.

communications infrastructure or our international acquisitions, any of which laws, fees or requirements may be applied retroactively or with significant delay;

promulgated by jurisdictions.

We are currently analyzing our qualification as an Excluded Entity as a “Real Estate Investment Vehicle.” In the event we do not qualify as a Real Estate Investment Vehicle, Top-Up Taxes may apply beginning in fiscal year 2026 on our United States income and may be material.

Safe harbor exceptions are expected to apply for the majority of our non-United States income, and for those entities that do not meet certain safe harbor tests, the impact to us as a whole is expected to be immaterial.

Developments will be monitored as guidance and local implementation progresses.

In 2021, we adopted science-based greenhouse gas reduction targets, which were approved by the Science Based Targets initiative and are in line with the goals set forth in the 2015 Paris Agreement.

Our ability to achieve these goals are based on several factors, some of which are outside of our control including changing regulatory requirements, the pace of changes in technology and the availability of requisite financing.

With changes to our portfolio, such as the divestiture of India and the CoreSite Acquisition, our ability to meet these goals may also be impacted.

In addition, to meet our goals, we may need to expend significant resources, which could increase our operational costs.

We cannot guarantee that we will achieve our announced environmental, social and governance goals and initiatives.

In addition, consumers’ perceptions of our efforts to achieve these goals often differ widely and present risks to our reputation and brand.

Failing to meet these goals could result in customer dissatisfaction and damage to our reputation with our key stakeholders, which could in turn adversely impact our results of operations, reputation, financial condition and stock price.

The results of an audit and examination of

If we were held

Our international expansion initiatives are subject to additional risks, such as those described above, as well as our ability to comply with bribery and anti-corruption laws such as the Foreign Corrupt Practices Act (the “FCPA”) and similar local laws.

These could result from numerous factors, including limited

We have service level commitment obligations to substantially all of our data center customers.

As a result, service interruptions, increased construction costs, significant equipment damage in our data centers and failing to recruit and develop qualified personnel could result in difficulty maintaining service level commitments to these customers and potential claims related to such failures.

In addition, any loss of service, equipment damage or inability to meet our service level commitment obligations could reduce the confidence of our customers and could consequently impair our ability to obtain and retain customers, which would adversely affect both our ability to generate revenues and our operating results.

Furthermore, we are dependent upon internet service providers, telecommunications carriers and utility providers, some of which have experienced significant system failures and outages in the past.

Our customers may in the future experience difficulties due to system failures unrelated to our systems and offerings.

Our platform expansion growth initiatives may not be successful, or we may be required to record impairment charges for our goodwill or for other intangible assets, which could have an adverse effect on our business, results of operations or financial condition, and could limit our continued investments in such platform expansion initiatives.

Public perception of possible health risks associated with cellular and other wireless communications technology could slow the growth of wireless companies, which could in turn slow our growth.

In particular, negative public perception of, and regulations regarding, these perceived health risks, including claims that the deployment of 5G networks is linked to adverse health effects, could undermine the market acceptance of wireless communications services and increase opposition to the development and expansion of tower sites.

If a scientific study, court decision, government agency ruling, or misinformation, disinformation or

During the year ended December 31, 2024, we completed the sale of ATC [removed: TIPL.][added: TIPL (as defined below).]

See Note [removed: 22] [added: 21] for further discussion.

Prior to the divestiture and classification as discontinued operations, ATC TIPL’s operating results were included within the [removed: Asia-Pacific] [added: Africa & APAC] property segment.

[removed: As a result, we now] [added: We] report our results in six segments: U.S. & Canada property (which includes all assets in the United States and Canada, other than our data center facilities and related assets), Africa & APAC property, Europe property, Latin America property, Data Centers and Services.

In evaluating financial performance in each business segment, management uses, among other factors, segment gross margin and segment operating profit (see note [removed: 20] [added: 19] to our consolidated financial statements included in this Annual Report).

We refer to the business encompassing the above as our property operations, which accounted for [removed: 98%] [added: 97%] of our total revenues for the year ended December 31, [removed: 2024] [added: 2025] and includes our U.S. & Canada property, Africa & APAC property, Europe property and Latin America property segments and Data Centers segment.

[removed: We also offer tower-related] [added: Our] services [removed: in the United States, including site application, zoning and permitting, structural and mount analyses, and construction management, which] [added: operations] primarily support our site leasing business, including the addition of new tenants and equipment on our sites.

The following table details the number of communications sites, excluding managed sites, that we owned or operated as of December 31, [removed: 2024:][added: 2025:]

| South Africa | | | | | | [removed: 2,517] [added: 2,483] | | | | | | — | | | | | | — | | |

| Africa & APAC total | | | | | | [removed: 26,569] [added: 27,762] | | | | | | — | | | | | | [removed: 73] [added: 95] | | |

| France | | | | | | [removed: 4,189] [added: 4,279] | | | | | | 303 | | | | | | 9 | | |

| Europe total | | | | | | [removed: 31,473] [added: 32,211] | | | | | | 303 | | | | | | 10 | | |

| Peru | | | | | | [removed: 3,976] [added: 3,968] | | | | | | 450 | | | | | | 1 | | |

As of December 31, [removed: 2024,] [added: 2025,] our property portfolio included [removed: 29] [added: 30] operating data center facilities across [removed: ten] [added: eleven] markets in the United States that collectively comprise approximately [removed: 3.3] [added: 3.7] million NRSF of data center space, as detailed below:

| San Francisco Bay, CA | | | | | | 9 | | | | | | [removed: 998] [added: 1,051] | | |

| Northern Virginia, VA | | | | | | [removed: 5] [added: 3] | | | | | | [removed: 651] [added: 627] | | |

| New York, NY | | | | | | [removed: 2] [added: 3] | | | | | | [removed: 285] [added: 376] | | |

| Miami, FL | | | | | | 2 | | | | | | [removed: 89] [added: 90] | | |

| Denver, CO | | | | | | 2 | | | | | | [removed: 38] [added: 151] | | |

Accordingly, the vast majority of the revenue generated by our property operations during the year ended December 31, [removed: 2024] [added: 2025] was recurring revenue that we should continue to receive in [added: future periods.]

Based upon existing customer leases and foreign currency exchange rates as of December 31, [removed: 2024,] [added: 2025,] we expect to generate [removed: nearly] [added: over] $54 billion of non-cancellable customer lease revenue over future periods, before the impact of straight-line lease accounting.

See [removed: discussion below and] Note [removed: 22] [added: 21] for further discussion.

During the year ended December 31, [removed: 2024,] [added: 2025,] churn was approximately 2% of our tenant billings, primarily driven by churn in our U.S. & Canada property segment, as discussed below.

This [removed: rate, in turn,] [added: rate of wireless network investment] is influenced by the growth of wireless services, the penetration of advanced wireless devices, the level of emphasis on network quality and capacity in carrier competition, the financial performance of our tenants and their access to capital and general economic conditions.

- [removed: Subscribers’ use of] [added: Rapid growth in] mobile data [added: consumption] continues to [removed: grow rapidly given] [added: be driven by] increasing smartphone and other advanced device penetration, the proliferation of bandwidth-intensive applications on these devices and the continuing evolution of the mobile ecosystem.

- [removed: Wireless service providers continue to acquire additional spectrum,] [added: Continued spectrum acquisition] and [removed: as a result are] [added: deployment by wireless service providers, which is] expected to [removed: add] [added: result in] additional sites and equipment [removed: to their networks] [added: on existing sites] as [removed: they seek to] [added: operators] optimize [removed: their] network configuration and utilize [added: the] additional spectrum.

[removed: These technologies may include] [added: - Emerging next generation technologies, such as] edge computing functionality, autonomous vehicle networks and a number of other internet-of-things, or IoT, [removed: applications, as well as] [added: applications and] other potential use cases for wireless [removed: services.][added: services requiring wireless connectivity.]

- Continued data growth, including through increased use of [removed: artificial intelligence,] [added: AI,] and emerging high-performance, latency-sensitive [removed: applications] [added: applications,] will drive an increased need for reliable, secure and interconnected data center solutions.

As a result, we expect to be able to leverage our extensive international portfolio of approximately [removed: 107,000] [added: 108,000] communications sites and the relationships we have built with our carrier tenants to drive sustainable, long\-term growth.

Demand for our communications infrastructure assets could be negatively impacted by a number of factors, including [added: increased competition within our industries,] an increase in network sharing or consolidation among our customers and financial difficulties for our customers, as set forth in Item 1A of this Annual Report under the captions “Risk Factors—If our customers consolidate their operations, exit their businesses or share site infrastructure to a significant degree, our [removed: growth, revenue] [added: growth] and [removed: ability to generate positive cash flows] [added: revenue] could be materially and adversely [removed: affected”] [added: affected,” “Risk Factors—Increasing competition within our industries may materially] and [added: adversely affect our revenue” and] “Risk Factors—A substantial portion of our current and projected future revenue is derived from a small number of customers, and we are sensitive to adverse changes in the creditworthiness and financial strength of our customers.” In addition, the emergence and growth of new technologies could reduce demand for our sites, as set forth under the caption “Risk Factors—New technologies or changes, or lack thereof, in our or a customer’s business model could make our communications infrastructure leasing business less desirable and result in decreasing revenues and operating results.” Further, our customers may be subject to new regulatory policies from time to time that materially and adversely affect the demand for our communications infrastructure assets.

*Property Operations New Site Revenue Growth.* During the year ended December 31, [removed: 2024,] [added: 2025,] we grew our portfolio of communications real estate through the acquisition and construction of approximately [removed: 2,450] [added: 2,230] communications sites globally.

| New Sites (Acquired or Constructed) | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | |

| U.S. & Canada | | | [removed: 15] [added: 155] | | | | | | [removed: 20] [added: 15] | | | | | | [removed: 55] [added: 20] | | |

| Africa & APAC (1) | | | [removed: 1,660] [added: 1,265] | | | | | | [removed: 1,700] [added: 1,660] | | | | | | [removed: 2,285] [added: 1,700] | | |

| Europe | | | [removed: 590] [added: 745] | | | | | | [removed: 555] [added: 590] | | | | | | [removed: 690] [added: 555] | | |

| Latin America | | | [removed: 185] [added: 65] | | | | | | [removed: 215] [added: 185] | | | | | | [removed: 340] [added: 215] | | |

(1)For the years ended December 31, [removed: 2024, 2023] [added: 2024] and [removed: 2022,] [added: 2023,] excludes approximately [removed: 90, 865,] [added: 90] and [removed: 4,035] [added: 865] new sites in India, respectively.

Our profit margin growth is therefore positively impacted by the addition of new customers to our sites or facilities but can be temporarily diluted by our development [added: or expansion] activities.

Nareit FFO attributable to American Tower Corporation common stockholders is defined as net income before gains or losses from the sale or disposal of real estate, real estate related impairment charges, real estate related depreciation, amortization and [removed: accretion] [added: accretion, and] including adjustments and distributions for unconsolidated affiliates and noncontrolling interests and [added: adjustments for] discontinued operations.

Years Ended December 31, [removed: 2024, 2023] [added: 2025] and [removed: 2022][added: 2024]

During the year ended December 31, 2025, we completed the sale of our fiber assets in South Africa (“South Africa Fiber”).

Prior to the divestiture, the operating results of South Africa Fiber were included within the Africa & APAC property segment.

We also offer tower-related services in the United States, including site application, zoning and permitting, structural and mount analyses, and construction management, together with program management offerings that support customer deployment needs from project scoping through construction.

| United States | | | | | | 26,714 | | | | | | 14,855 | | | | | | 429 | | |

| U.S. & Canada total | | | | | | 26,940 | | | | | | 14,855 | | | | | | 429 | | |

| Bangladesh | | | | | | 1,040 | | | | | | — | | | | | | — | | |

| Ghana | | | | | | 3,438 | | | | | | — | | | | | | 37 | | |

| Kenya | | | | | | 4,500 | | | | | | — | | | | | | 11 | | |

| Niger | | | | | | 931 | | | | | | — | | | | | | — | | |

| Nigeria | | | | | | 9,706 | | | | | | — | | | | | | — | | |

| Philippines | | | | | | 384 | | | | | | — | | | | | | — | | |

| Uganda | | | | | | 4,547 | | | | | | — | | | | | | 47 | | |

| Germany | | | | | | 15,501 | | | | | | — | | | | | | — | | |

| Spain | | | | | | 12,431 | | | | | | — | | | | | | 1 | | |

| Argentina | | | | | | 497 | | | | | | — | | | | | | 11 | | |

| Brazil | | | | | | 20,829 | | | | | | 1,434 | | | | | | 126 | | |

| Chile | | | | | | 3,681 | | | | | | — | | | | | | 107 | | |

| Colombia | | | | | | 4,858 | | | | | | — | | | | | | 6 | | |

| Mexico | | | | | | 8,689 | | | | | | 185 | | | | | | 75 | | |

| Paraguay | | | | | | 1,450 | | | | | | — | | | | | | — | | |

| Latin America total | | | | | | 44,684 | | | | | | 2,069 | | | | | | 328 | | |

| Total | | | | | | 131,597 | | | | | | 17,227 | | | | | | 862 | | |

| Chicago, IL | | | | | | 2 | | | | | | 272 | | |

| Boston, MA | | | | | | 1 | | | | | | 124 | | |

| Washington, D.C. | | | | | | 2 | | | | | | 47 | | |

| Total | | | | | | 30 | | | | | | 3,661 | | |

*AT&T Mexico Dispute.* We are currently engaged in an Arbitration with AT&T Mexico.

AT&T Mexico, which represented approximately $300 million of tenant revenue in 2025, is challenging the calculation of the monthly lease amount established under the MLA, as well as certain other provisions of the MLA, seeking rent abatement both retroactively and prospectively, and had been withholding tower rents since the start of 2025.

We incurred approximately $30 million of reserves during the year ended December 31, 2025 related to this customer.

We expect to record future reserves until the Arbitration is settled.

We believe we have meritorious defenses to the claims raised in this Arbitration, are vigorously defending the full enforceability of the MLA and remain confident in the terms and conditions of the MLA.

The Arbitration is scheduled for a hearing in August 2026.

On September 23, 2025, we and AT&T Mexico reached an agreement pursuant to which AT&T Mexico will remit payment of the majority of the withheld tower rents and will resume monthly payments of the majority of its owed tower rents.

The remainder of the outstanding receivables and the future monthly tower rent amounts not remitted directly to us will be deposited into an irrevocable escrow account, overseen by an independent trustee, to be released in accordance with a final ruling in the Arbitration or by mutual consent of us and AT&T Mexico.

*DISH Dispute.* On September 24, 2025, DISH delivered a notice purporting to be excused from its contractual obligations under the SCA.

DISH has failed to meet its payment obligations, and as of January 2026 is in default under the SCA.

We remain confident that DISH has not been excused from its obligations under the SCA, and that the SCA remains in full force and effect.

On October 20, 2025, we filed a complaint in the U.S. District Court for the District of Colorado seeking a declaratory judgment that DISH has not been excused from its obligations under the SCA, that the SCA remains in full force and effect, and that DISH remains required to perform all of its obligations under the SCA.

DISH represented approximately 2% and 4% of our total annual property revenue and total annual U.S. & Canada property revenue, respectively, for 2025.

Strong industry tailwinds also underpin our data center business.

The divestiture qualified for presentation as discontinued operations.

During the year ended December 31, 2024, we also completed the sales of ATC Australia and ATC New Zealand.

The divestitures did not qualify for presentation as discontinued operations.

During the fourth quarter of 2024, following recent divestitures, including the ATC TIPL Transaction, and changes to our organizational structure, we reviewed and changed our reportable segments.

Our APAC property segment and our Africa property segment were combined into the Africa & APAC property segment.

Historical financial information included in Management’s Discussion and Analysis of Financial Condition and Results of Operations has been adjusted to reflect the change in reportable segments.

| United States | | | | | | 26,583 | | | | | | 14,979 | | | | | | 434 | | |

| U.S. & Canada total | | | | | | 26,809 | | | | | | 14,979 | | | | | | 434 | | |

| Bangladesh | | | | | | 900 | | | | | | — | | | | | | — | | |

| Ghana | | | | | | 3,477 | | | | | | — | | | | | | 37 | | |

| Kenya | | | | | | 4,272 | | | | | | — | | | | | | 11 | | |

| Niger | | | | | | 916 | | | | | | — | | | | | | — | | |

| Nigeria | | | | | | 9,079 | | | | | | — | | | | | | — | | |

| Philippines | | | | | | 373 | | | | | | — | | | | | | — | | |

| Uganda | | | | | | 4,302 | | | | | | — | | | | | | 25 | | |

| Germany | | | | | | 15,204 | | | | | | — | | | | | | — | | |

| Spain | | | | | | 12,080 | | | | | | — | | | | | | 1 | | |

| Argentina | | | | | | 498 | | | | | | — | | | | | | 11 | | |

| Brazil | | | | | | 21,171 | | | | | | 1,440 | | | | | | 124 | | |

| Chile | | | | | | 3,712 | | | | | | — | | | | | | 110 | | |

| Colombia | | | | | | 4,945 | | | | | | — | | | | | | 6 | | |

| Mexico | | | | | | 9,423 | | | | | | 186 | | | | | | 89 | | |

| Paraguay | | | | | | 1,451 | | | | | | — | | | | | | — | | |

| Latin America total | | | | | | 45,888 | | | | | | 2,076 | | | | | | 343 | | |

_______________

| Chicago, IL | | | | | | 2 | | | | | | 216 | | |

| Boston, MA | | | | | | 1 | | | | | | 143 | | |

| Total | | | | | | 29 | | | | | | 3,343 | | |

future periods.

In 2023, we initiated a strategic review of our India business, as further discussed below under “Results of Operations—Loss from Discontinued Operations, Net of Taxes.” The strategic review concluded in January 2024 with the signed agreement for the ATC TIPL Transaction.

The ATC TIPL Transaction received all government and regulatory approvals during the three months ended September 30, 2024.

On September 12, 2024, we completed the ATC TIPL Transaction and received total consideration of 182 billion INR (approximately $2.2 billion).

ATC TIPL’s operating results are presented as discontinued operations.

We expect that our churn rate in our U.S. & Canada property segment will remain elevated through 2025 due to contractual lease cancellations and non-renewals by T-Mobile, including legacy Sprint Corporation leases, pursuant to the terms of the T-Mobile MLA entered into in September 2020.

- In less advanced wireless markets where network deployments are in earlier stages, we expect these deployments to drive demand for our tower space as carriers seek to expand their footprints and increase the scope and density of their networks.

We have established operations in many of these markets at the early stages of wireless development, which we believe will enable us to meaningfully participate in these deployments over the long term.

- Next generation technologies requiring wireless connectivity have the potential to provide incremental revenue opportunities for us.

In emerging markets, such as Bangladesh, Burkina Faso, Ghana, Kenya, Niger, Nigeria, the Philippines and Uganda, wireless networks tend to be significantly less advanced than those in the United States, and initial voice networks continue to be deployed in certain underdeveloped areas.

A majority of consumers in these markets still utilize basic wireless services and advanced device penetration remains low.

In more developed urban locations within these markets, mobile data usage tends to be higher and advanced network deployments are further along.

The following table provides information as of December 31, [removed: 2024] [added: 2025] about our market risk exposure associated with changing interest rates.

| Long-Term Debt | | | [removed: 2025] [added: 2026] | | | | | | [removed: 2026] [added: 2027] | | | | | | [removed: 2027] [added: 2028] | | | | | | [removed: 2028] [added: 2029] | | | | | | [removed: 2029] [added: 2030] | | | | | | Thereafter | | | | | | Total | | | | | | Fair Value | | | | | |

| Weighted-Average Interest Rate (b)(c) | | | [removed: —] [added: 9.50] | | % | | | | [removed: —] [added: 9.50] | | % | | | | [removed: 5.56] [added: 4.84] | | % | | | | — | | % | | | | — | | % | | | | [removed: —] [added: 13.50] | | % | | | | | | | | | | | | | | | |

(a) Fixed rate debt consisted [removed: of:] [added: of (i)] Securities issued in the Trust [removed: Securitizations; Securities issued in the 2015 Securitization;] [added: Securitization, (ii)] our senior unsecured notes (see note 8 to our consolidated financial statements included in this Annual Report for a detailed description of all such senior unsecured [removed: notes);] [added: notes)] and [added: (iii)] other [removed: debt] [added: debt,] including finance leases.

(b) Variable rate debt consisted of [added: (i)] the 2021 [added: Multicurrency Credit Facility, which matures on January 28, 2028, (ii) the 2021] Term Loan, which matures on January [removed: 31, 2027.][added: 28, 2028, (iii) the CoreSite DE1 Note and (iv) the Bangladesh Term Loan.]

(c) Based on rates effective as of December 31, [removed: 2024.][added: 2025.]

Variable rate debt as of December 31, [removed: 2024] [added: 2025 primarily] consisted of [added: $380.0 million under the 2021 Multicurrency Credit Facility,] $1.0 billion under the 2021 Term [added: Loan, $4.0 million under the CoreSite DE1 Note and $1.2 million under the Bangladesh Term] Loan.

A 10% increase in current interest rates would result in an additional [removed: $5.6] [added: $6.7] million of interest expense for the year ended December 31, [removed: 2024.][added: 2025.]

For the year ended December 31, [removed: 2024, 32%] [added: 2025, 31%] of our revenues and [removed: 39%] [added: 40%] of our total operating expenses were denominated in foreign currencies.

As of December 31, [removed: 2024,] [added: 2025,] we have incurred intercompany debt that is not considered to be permanently reinvested, and similar unaffiliated balances that were denominated in a currency other than the functional currency of the subsidiary in which it is [added: recorded.]

An adverse change of 10% in the underlying exchange rates of our unsettled intercompany debt and similar unaffiliated balances would result in [removed: $13.4] [added: $12.6] million of unrealized losses that would be included in Other expense in our consolidated statements of operations for the year ended December 31, [removed: 2024.][added: 2025.]

An adverse change of 10% in the underlying exchange rates of our outstanding EUR debt [added: not designated as a non-derivative net investment hedge] would result in [removed: $0.9] [added: $0.4] billion of foreign currency losses that would be included in Other expense in our consolidated statements of operations for the year ended December 31, [removed: 2024.][added: 2025.]

| Fixed Rate Debt (a) | | | $ | 3,386.2 | | | | | $ | 4,724.9 | | | | | $ | 6,132.6 | | | | | $ | 3,782.0 | | | | | $ | 4,925.3 | | | | | $ | 13,098.7 | | | | | $ | 36,049.7 | | | | | $ | 34,748.2 | | | | |

| Weighted-Average Interest Rate (a) | | | 2.57 | | % | | | | 2.52 | | % | | | | 4.00 | | % | | | | 3.38 | | % | | | | 3.10 | | % | | | | 3.96 | | % | | | | | | | | | | | | | | | |

| Variable Rate Debt (b) | | | $ | 1.6 | | | | | $ | 1.8 | | | | | $ | 1,380.6 | | | | | $ | — | | | | | $ | — | | | | | $ | 1.2 | | | | | $ | 1,385.2 | | | | | $ | 1,385.2 | | | | |

As of December 31, 2025, we have 7.5 billion EUR (approximately $8.8 billion) denominated debt outstanding, of which approximately 4.7 billion EUR (approximately $5.5 billion) is designated as a non-derivative net investment hedge.

| Fixed Rate Debt (a) | | | $ | 3,693.0 | | | | | $ | 3,319.3 | | | | | $ | 4,466.7 | | | | | $ | 6,027.4 | | | | | $ | 3,677.0 | | | | | $ | 14,572.9 | | | | | $ | 35,756.3 | | | | | $ | 33,562.4 | | | | |

| Weighted-Average Interest Rate (a) | | | 2.69 | | % | | | | 2.59 | | % | | | | 2.57 | | % | | | | 4.06 | | % | | | | 3.45 | | % | | | | 3.56 | | % | | | | | | | | | | | | | | | |

| Variable Rate Debt (b) | | | $ | — | | | | | $ | — | | | | | $ | 1,000.0 | | | | | $ | — | | | | | $ | — | | | | | $ | — | | | | | $ | 1,000.0 | | | | | $ | 1,000.0 | | | | |

recorded.

As of December 31, 2024, we have 7.5 billion EUR (approximately $7.8 billion) denominated debt outstanding.

We refer to this business, inclusive of our data center business discussed below, as our property operations, which accounted for [removed: 98%] [added: 97%] of our total revenues for the year ended December 31, [removed: 2024.][added: 2025.]

[removed: These] [added: Our] services [removed: include site application, zoning and permitting, structural and mount analyses, and construction management, which] [added: operations] primarily support our site leasing business, including the addition of new tenants and equipment on our sites.

As of December 31, [removed: 2024,] [added: 2025,] our communications real estate portfolio of [removed: 148,957] [added: 149,686] communications sites included [removed: 42,222] [added: 42,224] communications sites in the U.S. & Canada, [removed: 26,642] [added: 27,857] communications sites in Africa & APAC (as defined below), [removed: 31,786] [added: 32,524] communications sites in Europe and [removed: 48,307] [added: 47,081] communications sites in Latin America, as well as (i) urban telecommunications assets in Argentina, Brazil, [removed: Colombia, South Africa] [added: Colombia] and Spain, (ii) other property interests in Canada and the United States and (iii) [removed: 29] [added: 30 operating] data center facilities across [removed: ten] [added: eleven] markets in the United States.

See note [removed: 22] [added: 21] to our consolidated [removed: and condensed consolidated] financial statements included in this Annual Report (“Note [removed: 22”)] [added: 21”)] for further discussion.

As of December 31, [removed: 2024,] [added: 2025,] our REIT-qualified businesses included our U.S. tower leasing business, a majority of our U.S. DAS networks business, our Services and Data Centers segments, as well as most of our operations in Canada, Costa Rica, France, Germany, Ghana, Kenya, Mexico, Nigeria, South Africa, Spain and Uganda.

[removed: As a result, we now have] [added: We report our results in] six [removed: reportable] segments: U.S. & Canada property (which includes all assets in the United States and Canada, other than our data center facilities and related assets), Africa & [removed: APAC] [added: Asia-Pacific (“APAC”)] property, Europe property, Latin America property, Data Centers and Services.

Our property operations accounted for [removed: 98%, 99% and] [added: 97%,] 98% [added: and 99%] of our total revenues for the years ended December 31, [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022,] [added: 2023,] respectively.

Based upon foreign currency exchange rates and the tenant leases in place as of December 31, [removed: 2024,] [added: 2025,] we expect to generate [removed: nearly] [added: over] $54 billion of non-cancellable tenant lease revenue over future periods, before the impact of straight-line lease accounting.

We derive our churn rate for a given year by dividing our tenant billings [added: lost on this basis by our prior-year tenant billings.]

During the year ended December 31, [removed: 2024,] [added: 2025,] churn was approximately 2% of our tenant billings, primarily driven by churn in our U.S. & Canada property segment.

Our property business includes the operation of communications sites and managed networks, the leasing of property interests and, in select markets, the operation of fiber, the operation of data centers and the provision of backup power through shared [removed: generators.][added: generators and power solutions.]

| | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | |

| U.S. & Canada | | | [removed: 52] [added: 49] | | % | | | | [removed: 53] [added: 52] | | % | | | | [removed: 52] [added: 53] | | % |

| Africa & APAC (1) | | | [removed: 12] [added: 13] | | % | | | | 12 | | % | | | | 12 | | % |

| Europe | | | [removed: 8] [added: 9] | | % | | | | 8 | | % | | | | 8 | | % |

| Latin America | | | [removed: 17] [added: 15] | | % | | | | [removed: 18] [added: 17] | | % | | | | 18 | | % |

| Data Centers | | | [removed: 9] [added: 10] | | % | | | | [removed: 8] [added: 9] | | % | | | | 8 | | % |

[removed: (1) Excludes the operating results of] [added: Ltd. and] ATC [removed: TIPL,] [added: Telecom Infrastructure Private Limited (“ATC TIPL”),] which are reported as discontinued operations.

*Communications Sites.* Approximately [removed: 87%, 88% and] [added: 82%,] 87% [added: and 88%] of revenue in our property segments was attributable to our communications sites, excluding [added: data center facilities and related assets,] DAS networks and fiber, for the years ended December 31, [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022,] [added: 2023,] respectively.

Our top tenants by revenue for each property segment are as follows for the year ended December 31, [removed: 2024:][added: 2025:]

- U.S. & Canada: AT&T Inc. (“AT&T”); [removed: T-Mobile;] [added: T-Mobile US, Inc. (“T-Mobile”);] and Verizon Communications Inc. (“Verizon Wireless”) accounted for an aggregate of [removed: 86%] [added: 85%] of U.S. & Canada property segment revenue.

- Latin America: América Móvil; AT&T; Telefónica; and TIM S.p.A. accounted for an aggregate of [removed: 74%] [added: 71%] of Latin America property segment revenue.

[removed: *Managed Networks, Data] [added: *Data] Centers and Related Assets, [added: Managed Networks,] Other Telecommunications Assets, Property Interests and Shared [removed: Generators.*] [added: Generators and Power Solutions.*] In addition to our communications sites, we also own and operate several types of managed network solutions, provide communications site management services to third parties, manage and lease property interests under carrier or other third-party communications sites, operate data center facilities and related assets, operate other telecommunications assets and provide back-up power sources [added: and power solutions] to tenants at our sites.

[removed: *•*Managed] [added: - Managed] Networks. We own and operate DAS networks in the United States and certain international markets.

[removed: - Data] [added: *•*Data] Centers and Related Assets. We own and operate data center facilities and related assets in the United States, which consist of specialized and secure buildings that house networking, storage and communications technology infrastructure, including servers, storage devices, switches, routers and fiber optic transmission equipment.

*•*Shared [removed: Generators.] [added: Generators and Power Solutions.] We have contracts with certain of our [added: tower] tenants [removed: in the United States] pursuant to which we provide access to shared backup power [removed: generators.][added: generators in the United States.]

We offer tower-related services in the United States, including site application, zoning and permitting, structural and mount analyses, and construction management [removed: services.][added: services, together with program management offerings that support customer deployment needs from project scoping through construction.]

This segment accounted for [removed: 2%, 1% and] [added: 3%,] 2% [added: and 1%] of our total revenue for the years ended December 31, [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022,] [added: 2023,] respectively.

[removed: A significant portion of our inorganic growth has been focused on properties with lower initial] tenancy because we believe that over time we can significantly increase tenancy levels, and therefore, drive strong returns on those assets.

More recently, we have invested in strategic data center assets, including through our acquisition of CoreSite Realty Corporation [removed: (“CoreSite,” and the acquisition, the “CoreSite Acquisition”)] [added: (“CoreSite”)] in late [removed: 2021,] [added: 2021 (the “CoreSite Acquisition”),] which we believe can drive strong, recurring growth and also meaningfully enhance the value of our existing communications tower real estate through emerging edge compute opportunities in the future.

We are also focused on developing and implementing [removed: sustainable] power solutions across our footprint to [removed: reduce our reliance on fossil fuels and] help improve the overall efficiency of the communications infrastructure and wireless industries through our [removed: sustainability and] power as a service (PaaS) initiatives.

We continue to focus on maintaining a robust liquidity position and, as of December 31, [removed: 2024,] [added: 2025,] had [removed: $12.0] [added: $11.1] billion of available liquidity.

On an ongoing basis, we also perform a comprehensive assessment of our global operations to ensure our portfolio is positioned to drive sustained growth [added: and achieve our risk-adjusted return objectives.]

[removed: This] [added: Conversely, this] assessment can influence our [removed: decisions on future capital allocation priorities between certain countries and assets, and may result in our] decision to divest a portion, or all, of certain assets, including our Mexico fiber and Poland businesses in 2023, [removed: and] our Australia, India and New Zealand businesses in [removed: 2024,] [added: 2024] and [added: our South Africa fiber business in 2025, and] repurpose proceeds, and potential future capital, to other capital [removed: priorities.][added: priorities, including investments into developed markets.]

[removed: We strive to maintain a diversified approach to our] international strategy by operating in a geographically diverse array of markets in a variety of stages of wireless network development.

[removed: - Country analysis. Prior to entering a new market, and on an ongoing basis] [added: Specifically] as [removed: we evaluate] [added: part of] our [removed: portfolio,] [added: ongoing portfolio analysis,] we conduct an extensive review of [removed: the] [added: a particular] country’s historical and projected macroeconomic fundamentals, including inflation and foreign currency exchange rate trends, demographics, capital markets, tax regime and investment alternatives, and the general business, political and legal environments, including property rights and regulatory regime.

In Africa & APAC, our subsidiaries in Burkina Faso, Ghana, Kenya, Niger, Nigeria and Uganda are required to hold a license in order to establish and maintain passive telecommunications infrastructure services and DAS networks for communications [added: service providers.]

The subsidiary that holds our fiber business in Brazil is also licensed and regulated as [removed: a concession holder and permit] [added: an authorization] holder [removed: authorized] to provide telecommunications services.

Our foreign operations may be affected if a country’s regulatory authority restricts, revokes or modifies spectrum licenses of certain wireless service providers or implements [added: modifications or] limitations on foreign ownership.

[removed: It also prohibits state or local restrictions] based on the environmental effects of radio frequency emissions to the extent the facilities comply with FCC regulations.

These services include site application, zoning and permitting, structural and mount analyses, and construction management services, together with program management offerings that support customer deployment needs from project scoping through construction.

(1) For the years ended December 31, 2024 and 2023, excludes the operating results of our subsidiaries, ATC Asia Pacific Pte.

In Africa, we also have contracts to power our

tower tenants’ equipment through the use of shared infrastructure assets, primarily consisting of generators, solar panels and electricity storage solutions.

A significant portion of our inorganic growth has been focused on properties with lower initial

This assessment can influence our decisions on future capital allocation priorities between certain countries and assets, and may result in our decision to prioritize investments into developed markets, including the U.S. & Canada, Europe and the data centers markets.

Our international strategy incorporates portfolio analysis, capital prioritization and the disciplined management of overseas cash, including repatriation where feasible.

We strive to maintain a diversified approach to our

We also analyze (i) the competitiveness of the country’s wireless market and (ii) how a particular market fits within our long-term strategic objectives.

In Peru, our subsidiaries are registered as infrastructure providers.

It also prohibits state or local restrictions

In some markets, our data centers are subject to zoning restrictions imposed by local authorities.

While these regulations vary, they may require data center operators to obtain approval from local authorities or environmental bodies prior to data center construction or modification of an existing facility.

Local authorities and community residents periodically oppose construction in their communities, which can delay or prevent new data center construction, thereby limiting our ability to respond to tenant demand.

This opposition and existing or new zoning or environmental regulations can increase costs associated with new data center construction or modifications to existing facilities, as well as adversely affect the associated timing or cost of such projects.

There are frequently new market participants that create additional competition.

Furthermore, as part of our efforts to globalize our operations, we created a new global Health & Safety (“H&S”) function tasked with strengthening our H&S policies and culture, ensuring compliance with global and local regulations and fostering a proactive safety-first mindset across all organizational levels.

In 2023, we undertook a strategic review of our India operations, where we evaluated the appropriate level of exposure to the India market within our global portfolio of communications assets, and assessed opportunities to repurpose capital to drive long-term shareholder value and sustained growth.

The strategic review concluded in January 2024 with the signed agreement for the ATC TIPL Transaction (as defined below).

On January 4, 2024, we, through our subsidiaries, ATC Asia Pacific Pte.

Ltd. and ATC Telecom Infrastructure Private Limited (“ATC TIPL”), which held our operations in India, entered into an agreement with Data Infrastructure Trust (“DIT”), an infrastructure investment trust sponsored by an affiliate of Brookfield Asset Management, pursuant to which DIT agreed to acquire a 100% ownership interest in ATC TIPL (the “ATC TIPL Transaction”).

Per the terms of the agreement, total aggregate consideration represented up to approximately 210 billion Indian Rupees (“INR”) (approximately $2.5 billion), including the value of the VIL OCDs and the VIL Shares (each as defined and further discussed in Item 7 of this Annual Report under the caption “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Results of Operations—Loss from Discontinued Operations, Net of Taxes”), payments on certain existing customer receivables, the repayment of existing intercompany debt and the repayment, or assumption, of our existing term loan in India, by DIT.

During the year ended December 31, 2024, ATC TIPL distributed approximately 29.6 billion INR (approximately $354.1 million) to us, which included the value of the VIL Shares and the VIL OCDs and the satisfaction of the economic benefit associated with the rights to payments on certain existing customer receivables.

The distributions were deducted from the total aggregate consideration received by us at closing.

The ATC TIPL Transaction received all government and regulatory approvals during the three months ended September 30, 2024, and on September 12, 2024, we completed the sale of ATC TIPL and received total consideration of 182 billion INR (approximately $2.2 billion).

We used the proceeds from the ATC TIPL Transaction to repay existing indebtedness under our $6.0 billion senior unsecured multicurrency revolving credit facility, as amended and restated in December 2021, as further amended (the “2021 Multicurrency Credit Facility”).

The divestiture qualified for presentation as discontinued operations.

We recorded a loss on the sale of ATC TIPL of $1.2 billion, which primarily included the reclassification of our cumulative translation adjustment in India upon exiting the market of $1.1 billion.

The loss on sale of ATC TIPL is included in Loss from discontinued operations, net of taxes in the consolidated statements of operations for the year ended December 31, 2024.

During the year ended December 31, 2024, we also completed the sales of our subsidiaries in Australia (“ATC Australia”) and New Zealand (“ATC New Zealand”) for total aggregate consideration of approximately $77.6 million.

We recorded a gain on the sales of ATC Australia and ATC New Zealand of $8.5 million, which is included in Other operating expenses in the accompanying consolidated statements of operations.

The divestitures did not qualify for presentation as discontinued operations.

During the fourth quarter of 2024, following recent divestitures, including the ATC TIPL Transaction, and changes to our organizational structure, we reviewed and changed our reportable segments.

Our Asia-Pacific (“APAC”) property segment and our Africa property segment were combined into the Africa & APAC property segment.

This change aligns with our management structure and better aligns our reporting with management’s current approach of allocating costs and resources, managing growth and profitability and assessing the operating performance of our business segments.

lost on this basis by our prior-year tenant billings.

We expect that our churn rate in our U.S. & Canada property segment will continue to be elevated through 2025 due to contractual lease cancellations and non-renewals by T-Mobile US, Inc. (“T-Mobile”), including legacy Sprint Corporation leases, pursuant to the terms of our master lease agreement with T-Mobile (the “T-Mobile MLA”) entered into in September 2020.

See Note 22 for further discussion.

and achieve our risk-adjusted return objectives.

Our international strategy includes a disciplined, individualized market evaluation, in which we conduct the following analyses, among others:

- Wireless industry analysis. To confirm the presence of sufficient demand to support an independent tower leasing model, we analyze the competitiveness of the country’s wireless market.

This includes an evaluation of the industry’s pricing environment, past and potential consolidation and the stage of its wireless network development.

Characteristics that result in an attractive investment opportunity include (i) multiple competitive wireless service providers who are actively seeking to invest in deploying voice and data networks and (ii) ongoing or expected deployment of incremental spectrum from recent or anticipated auctions.

- Opportunity and counterparty analysis. Once an investment opportunity is identified within a geographic area with an attractive wireless industry, we conduct a multifaceted opportunity and counterparty analysis.

This includes evaluating (i) the type of transaction, (ii) its ability to meet our risk-adjusted return criteria given the country and the counterparties involved, including the anticipated anchor tenant and (iii) how the transaction fits within our long-term strategic objectives, including future potential investment and expansion within the region.

service providers.

In Peru, our subsidiaries are registered as infrastructure providers and in Colombia, passive infrastructure activities do not need any authorization, but our fiber subsidiary is registered as a carrier service provider.

*Data Centers*.

*Inclusion and Belonging*.

Furthermore, we have worked to provide access and opportunity for underrepresented groups in the REIT industry.

We also enable global employee resource groups to promote better employee engagement.

*Workplace Safety*.

[removed: In the opinion of] [added: While our] management, after consultation with counsel, [removed: there are no matters] currently [removed: pending that would, in] [added: believes] the [removed: event] [added: ultimate outcome] of [removed: an adverse outcome,] [added: these legal proceedings, individually and in the aggregate, will not] have a material [added: adverse] impact on our consolidated financial position, results of operations or [removed: liquidity.][added: liquidity, litigation is subject to inherent uncertainties.]

Were an unfavorable ruling to occur, there exists the possibility of a material adverse impact on our financial condition and results of operations.

*AT&T Mexico Dispute*

We are currently engaged in an Arbitration with AT&T Mexico.

AT&T Mexico, which represented approximately $300 million of tenant revenue in 2025, is challenging the calculation of the monthly lease amount established under the MLA, as well as certain other provisions of the MLA, seeking rent abatement both retroactively and prospectively, and had been withholding tower rents since the start of 2025.

We incurred approximately $30 million of reserves during the year ended December 31, 2025 related to this customer.

We expect to record future reserves until the Arbitration is settled.

We believe we have meritorious defenses to the claims raised in this Arbitration, are vigorously defending the full enforceability of the MLA and remain confident in the terms and conditions of the MLA.

The Arbitration is scheduled for a hearing in August 2026.

On September 23, 2025, we and AT&T Mexico reached an agreement pursuant to which AT&T Mexico will remit payment of the majority of the withheld tower rents and will resume monthly payments of the majority of its owed tower rents.

The remainder of the outstanding receivables and the future monthly tower rent amounts not remitted directly to us will be deposited into an irrevocable escrow account, overseen by an independent trustee, to be released in accordance with a final ruling in the Arbitration or by mutual consent of us and AT&T Mexico.

*DISH Dispute*

On September 24, 2025, DISH delivered a notice purporting to be excused from its contractual obligations under the SCA.

DISH has failed to meet its payment obligations, and as of January 2026 is in default under the SCA.

We remain confident that DISH has not been excused from its obligations under the SCA, and that the SCA remains in full force and effect.

On October 20, 2025, we filed a complaint in the U.S. District Court for the District of Colorado seeking a declaratory judgment that DISH has not been excused from its obligations under the SCA, that the SCA remains in full force and effect, and that DISH remains required to perform all of its obligations under the SCA.

DISH represented approximately 2% and 4% of our total annual property revenue and total annual U.S. & Canada property revenue, respectively, for 2025.

For the fiscal year ended December 31, [removed: 2024][added: 2025]

| [removed: 1.375%] [added: 3.625%] Senior Notes due [removed: 2025] [added: 2032] | | | AMT [removed: 25A] [added: 32B] | | | New York Stock Exchange | | |

The aggregate market value of the voting and non-voting common stock held by non-affiliates of the registrant as of June 30, [removed: 2024] [added: 2025] was [removed: $90.7] [added: $103.4] billion, based on the closing price of the registrant’s common stock as reported on the New York Stock Exchange as of the last business day of the registrant’s most recently completed second quarter.

As of February [removed: 18, 2025,] [added: 17, 2026,] there were [removed: 467,457,256] [added: 466,084,820] shares of common stock outstanding.

Portions of the definitive proxy statement (the “Definitive Proxy Statement”) to be filed with the Securities and Exchange Commission relative to the registrant’s [removed: 2025] [added: 2026] Annual Meeting of Stockholders are incorporated by reference into Part III of this Report.

FISCAL YEAR ENDED DECEMBER 31, [removed: 2024][added: 2025]

| [Special Note Regarding Forward-Looking [removed: Statements](#i9eb45799c76a40129d05d249625e314b_10)] [added: Statements](#i61f6369049ff4743af4eb2dd4bf56cf3_10)] | | | | | | [removed: [iii](#i9eb45799c76a40129d05d249625e314b_10)] [added: [iii](#i61f6369049ff4743af4eb2dd4bf56cf3_10)] | | |

| ITEM 1. | | | [removed: [Business](#i9eb45799c76a40129d05d249625e314b_16)] [added: [Business](#i61f6369049ff4743af4eb2dd4bf56cf3_16)] | | | [removed: [1](#i9eb45799c76a40129d05d249625e314b_16)] [added: [1](#i61f6369049ff4743af4eb2dd4bf56cf3_16)] | | |

| | | | [Products and [removed: Services](#i9eb45799c76a40129d05d249625e314b_22)] [added: Services](#i61f6369049ff4743af4eb2dd4bf56cf3_22)] | | | [removed: [2](#i9eb45799c76a40129d05d249625e314b_22)] [added: [2](#i61f6369049ff4743af4eb2dd4bf56cf3_22)] | | |

| | | | [Regulatory [removed: Matters](#i9eb45799c76a40129d05d249625e314b_28)] [added: Matters](#i61f6369049ff4743af4eb2dd4bf56cf3_28)] | | | [removed: [6](#i9eb45799c76a40129d05d249625e314b_28)] [added: [6](#i61f6369049ff4743af4eb2dd4bf56cf3_28)] | | |

| | | | [Human Capital [removed: Resources](#i9eb45799c76a40129d05d249625e314b_34)] [added: Resources](#i61f6369049ff4743af4eb2dd4bf56cf3_34)] | | | [removed: [8](#i9eb45799c76a40129d05d249625e314b_34)] [added: [8](#i61f6369049ff4743af4eb2dd4bf56cf3_34)] | | |

| | | | [Executive [removed: Officers](#i9eb45799c76a40129d05d249625e314b_37)] [added: Officers](#i61f6369049ff4743af4eb2dd4bf56cf3_37)] | | | [removed: [10](#i9eb45799c76a40129d05d249625e314b_37)] [added: [9](#i61f6369049ff4743af4eb2dd4bf56cf3_37)] | | |

| | | | [Available [removed: Information](#i9eb45799c76a40129d05d249625e314b_40)] [added: Information](#i61f6369049ff4743af4eb2dd4bf56cf3_40)] | | | [removed: [10](#i9eb45799c76a40129d05d249625e314b_40)] [added: [9](#i61f6369049ff4743af4eb2dd4bf56cf3_40)] | | |

| ITEM 1A. | | | [Risk [removed: Factors](#i9eb45799c76a40129d05d249625e314b_43)] [added: Factors](#i61f6369049ff4743af4eb2dd4bf56cf3_43)] | | | [removed: [10](#i9eb45799c76a40129d05d249625e314b_43)] [added: [10](#i61f6369049ff4743af4eb2dd4bf56cf3_43)] | | |

| ITEM 1B. | | | [Unresolved Staff [removed: Comments](#i9eb45799c76a40129d05d249625e314b_46)] [added: Comments](#i61f6369049ff4743af4eb2dd4bf56cf3_46)] | | | [removed: [21](#i9eb45799c76a40129d05d249625e314b_46)] [added: [22](#i61f6369049ff4743af4eb2dd4bf56cf3_46)] | | |

| ITEM 1C. | | | [removed: [Cybersecurity](#i9eb45799c76a40129d05d249625e314b_49)] [added: [Cybersecurity](#i61f6369049ff4743af4eb2dd4bf56cf3_49)] | | | [removed: [21](#i9eb45799c76a40129d05d249625e314b_49)] [added: [22](#i61f6369049ff4743af4eb2dd4bf56cf3_49)] | | |

| ITEM 2. | | | [removed: [Properties](#i9eb45799c76a40129d05d249625e314b_52)] [added: [Properties](#i61f6369049ff4743af4eb2dd4bf56cf3_52)] | | | [removed: [22](#i9eb45799c76a40129d05d249625e314b_52)] [added: [24](#i61f6369049ff4743af4eb2dd4bf56cf3_52)] | | |

| ITEM 3. | | | [Legal [removed: Proceedings](#i9eb45799c76a40129d05d249625e314b_55)] [added: Proceedings](#i61f6369049ff4743af4eb2dd4bf56cf3_55)] | | | [removed: [24](#i9eb45799c76a40129d05d249625e314b_55)] [added: [25](#i61f6369049ff4743af4eb2dd4bf56cf3_55)] | | |

| ITEM 4. | | | [Mine Safety [removed: Disclosures](#i9eb45799c76a40129d05d249625e314b_58)] [added: Disclosures](#i61f6369049ff4743af4eb2dd4bf56cf3_58)] | | | [removed: [24](#i9eb45799c76a40129d05d249625e314b_58)] [added: [26](#i61f6369049ff4743af4eb2dd4bf56cf3_58)] | | |

| ITEM 5. | | | [Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity [removed: Securities](#i9eb45799c76a40129d05d249625e314b_64)] [added: Securities](#i61f6369049ff4743af4eb2dd4bf56cf3_64)] | | | [removed: [25](#i9eb45799c76a40129d05d249625e314b_64)] [added: [27](#i61f6369049ff4743af4eb2dd4bf56cf3_64)] | | |

| | | | [Performance [removed: Graph](#i9eb45799c76a40129d05d249625e314b_70)] [added: Graph](#i61f6369049ff4743af4eb2dd4bf56cf3_70)] | | | [removed: [25](#i9eb45799c76a40129d05d249625e314b_70)] [added: [27](#i61f6369049ff4743af4eb2dd4bf56cf3_70)] | | |

| ITEM 6. | | | [removed: [\[Reserved\]](#i9eb45799c76a40129d05d249625e314b_76)] [added: [\[Reserved\]](#i61f6369049ff4743af4eb2dd4bf56cf3_76)] | | | [removed: [26](#i9eb45799c76a40129d05d249625e314b_76)] [added: [28](#i61f6369049ff4743af4eb2dd4bf56cf3_76)] | | |

| ITEM 7. | | | [Management’s Discussion and Analysis of Financial Condition and Results of [removed: Operations](#i9eb45799c76a40129d05d249625e314b_82)] [added: Operations](#i61f6369049ff4743af4eb2dd4bf56cf3_82)] | | | [removed: [27](#i9eb45799c76a40129d05d249625e314b_82)] [added: [29](#i61f6369049ff4743af4eb2dd4bf56cf3_82)] | | |

| | | | [Executive [removed: Overview](#i9eb45799c76a40129d05d249625e314b_85)] [added: Overview](#i61f6369049ff4743af4eb2dd4bf56cf3_85)] | | | [removed: [27](#i9eb45799c76a40129d05d249625e314b_85)] [added: [29](#i61f6369049ff4743af4eb2dd4bf56cf3_85)] | | |

| | | | [Non-GAAP Financial [removed: Measures](#i9eb45799c76a40129d05d249625e314b_88)] [added: Measures](#i61f6369049ff4743af4eb2dd4bf56cf3_88)] | | | [removed: [33](#i9eb45799c76a40129d05d249625e314b_88)] [added: [35](#i61f6369049ff4743af4eb2dd4bf56cf3_88)] | | |

| | | | [Results of Operations: Years Ended December 31, [removed: 2024, 2023] [added: 2025] and [removed: 2022](#i9eb45799c76a40129d05d249625e314b_91)] [added: 2024](#i61f6369049ff4743af4eb2dd4bf56cf3_91)] | | | [removed: [34](#i9eb45799c76a40129d05d249625e314b_91)] [added: [36](#i61f6369049ff4743af4eb2dd4bf56cf3_91)] | | |

| | | | [Liquidity and Capital [removed: Resources](#i9eb45799c76a40129d05d249625e314b_94)] [added: Resources](#i61f6369049ff4743af4eb2dd4bf56cf3_94)] | | | [removed: [46](#i9eb45799c76a40129d05d249625e314b_94)] [added: [45](#i61f6369049ff4743af4eb2dd4bf56cf3_94)] | | |

| | | | [Critical Accounting Policies and [removed: Estimates](#i9eb45799c76a40129d05d249625e314b_97)] [added: Estimates](#i61f6369049ff4743af4eb2dd4bf56cf3_97)] | | | [removed: [55](#i9eb45799c76a40129d05d249625e314b_97)] [added: [54](#i61f6369049ff4743af4eb2dd4bf56cf3_97)] | | |

| | | | [Accounting Standards [removed: Updates](#i9eb45799c76a40129d05d249625e314b_100)] [added: Updates](#i61f6369049ff4743af4eb2dd4bf56cf3_100)] | | | [removed: [58](#i9eb45799c76a40129d05d249625e314b_100)] [added: [56](#i61f6369049ff4743af4eb2dd4bf56cf3_100)] | | |

| ITEM 7A. | | | [Quantitative and Qualitative Disclosures About Market [removed: Risk](#i9eb45799c76a40129d05d249625e314b_103)] [added: Risk](#i61f6369049ff4743af4eb2dd4bf56cf3_103)] | | | [removed: [58](#i9eb45799c76a40129d05d249625e314b_103)] [added: [56](#i61f6369049ff4743af4eb2dd4bf56cf3_103)] | | |

| ITEM 8. | | | [Financial Statements and Supplementary [removed: Data](#i9eb45799c76a40129d05d249625e314b_106)] [added: Data](#i61f6369049ff4743af4eb2dd4bf56cf3_106)] | | | [removed: [59](#i9eb45799c76a40129d05d249625e314b_106)] [added: [57](#i61f6369049ff4743af4eb2dd4bf56cf3_106)] | | |

| ITEM 9. | | | [Changes in and Disagreements with Accountants on Accounting and Financial [removed: Disclosure](#i9eb45799c76a40129d05d249625e314b_109)] [added: Disclosure](#i61f6369049ff4743af4eb2dd4bf56cf3_109)] | | | [removed: [59](#i9eb45799c76a40129d05d249625e314b_109)] [added: [57](#i61f6369049ff4743af4eb2dd4bf56cf3_109)] | | |

| ITEM 9A. | | | [Controls and [removed: Procedures](#i9eb45799c76a40129d05d249625e314b_112)] [added: Procedures](#i61f6369049ff4743af4eb2dd4bf56cf3_112)] | | | [removed: [59](#i9eb45799c76a40129d05d249625e314b_112)] [added: [57](#i61f6369049ff4743af4eb2dd4bf56cf3_112)] | | |

| | | | [Disclosure Controls and [removed: Procedures](#i9eb45799c76a40129d05d249625e314b_115)] [added: Procedures](#i61f6369049ff4743af4eb2dd4bf56cf3_115)] | | | [removed: [59](#i9eb45799c76a40129d05d249625e314b_115)] [added: [57](#i61f6369049ff4743af4eb2dd4bf56cf3_115)] | | |

| | | | [Management’s Annual Report on Internal Control over Financial [removed: Reporting](#i9eb45799c76a40129d05d249625e314b_118)] [added: Reporting](#i61f6369049ff4743af4eb2dd4bf56cf3_118)] | | | [removed: [60](#i9eb45799c76a40129d05d249625e314b_118)] [added: [58](#i61f6369049ff4743af4eb2dd4bf56cf3_118)] | | |

| | | | [Changes in Internal Control over Financial [removed: Reporting](#i9eb45799c76a40129d05d249625e314b_121)] [added: Reporting](#i61f6369049ff4743af4eb2dd4bf56cf3_121)] | | | [removed: [60](#i9eb45799c76a40129d05d249625e314b_121)] [added: [58](#i61f6369049ff4743af4eb2dd4bf56cf3_121)] | | |

| | | | [Report of Independent Registered Public Accounting [removed: Firm](#i9eb45799c76a40129d05d249625e314b_124)] [added: Firm](#i61f6369049ff4743af4eb2dd4bf56cf3_124)] | | | [removed: [61](#i9eb45799c76a40129d05d249625e314b_124)] [added: [59](#i61f6369049ff4743af4eb2dd4bf56cf3_124)] | | |

| ITEM 9B. | | | [Other [removed: Information](#i9eb45799c76a40129d05d249625e314b_127)] [added: Information](#i61f6369049ff4743af4eb2dd4bf56cf3_127)] | | | [removed: [62](#i9eb45799c76a40129d05d249625e314b_127)] [added: [60](#i61f6369049ff4743af4eb2dd4bf56cf3_127)] | | |

| ITEM 9C. | | | [Disclosure Regarding Foreign Jurisdictions That Prevent [removed: Inspections](#i9eb45799c76a40129d05d249625e314b_133)] [added: Inspections](#i61f6369049ff4743af4eb2dd4bf56cf3_133)] | | | [removed: [62](#i9eb45799c76a40129d05d249625e314b_133)] [added: [60](#i61f6369049ff4743af4eb2dd4bf56cf3_133)] | | |

| ITEM 10. | | | [Directors, Executive Officers and Corporate [removed: Governance](#i9eb45799c76a40129d05d249625e314b_139)] [added: Governance](#i61f6369049ff4743af4eb2dd4bf56cf3_139)] | | | [removed: [63](#i9eb45799c76a40129d05d249625e314b_139)] [added: [61](#i61f6369049ff4743af4eb2dd4bf56cf3_139)] | | |

222 Berkeley Street

| | | | [Overview](#i61f6369049ff4743af4eb2dd4bf56cf3_19) | | | [1](#i61f6369049ff4743af4eb2dd4bf56cf3_19) | | |

| | | | [Strategy](#i61f6369049ff4743af4eb2dd4bf56cf3_25) | | | [4](#i61f6369049ff4743af4eb2dd4bf56cf3_25) | | |

| | | | [Competition](#i61f6369049ff4743af4eb2dd4bf56cf3_31) | | | [8](#i61f6369049ff4743af4eb2dd4bf56cf3_31) | | |

| | | | [Dividends](#i61f6369049ff4743af4eb2dd4bf56cf3_67) | | | [27](#i61f6369049ff4743af4eb2dd4bf56cf3_67) | | |

| | | | [Issuer Purchases of Equity Securities](#i61f6369049ff4743af4eb2dd4bf56cf3_73) | | | [28](#i61f6369049ff4743af4eb2dd4bf56cf3_73) | | |

FISCAL YEAR ENDED DECEMBER 31, 2025

| | | | | | | | | |

116 Huntington Avenue

| | | | [Overview](#i9eb45799c76a40129d05d249625e314b_19) | | | [1](#i9eb45799c76a40129d05d249625e314b_19) | | |

| | | | [Strategy](#i9eb45799c76a40129d05d249625e314b_25) | | | [5](#i9eb45799c76a40129d05d249625e314b_25) | | |

| | | | [Competition](#i9eb45799c76a40129d05d249625e314b_31) | | | [8](#i9eb45799c76a40129d05d249625e314b_31) | | |

| | | | [Dividends](#i9eb45799c76a40129d05d249625e314b_67) | | | [25](#i9eb45799c76a40129d05d249625e314b_67) | | |

In [removed: 2024,] [added: 2025,] the topics included, among other items, our focus on cybersecurity resilience, new cybersecurity [removed: initiatives] [added: initiatives, third-party risk] and our approach to responsible use of artificial intelligence.

Our steering committee includes our CISO, our Chief Information Officer, our Senior Vice President and Chief Security Officer, our Senior Vice President, Internal Audit, our [removed: Chief Technology Officer, our] Vice President, Corporate Legal, CoreSite’s Senior Vice President of IT & Digitization and CoreSite’s Vice President of Information Security and IT Infrastructure.

Our CISO has held information security and IT leadership positions across large organizations for [removed: eight] [added: nine] years, which included overseeing governance and compliance programs.

Our Chief Security Officer heads our converged physical and information security team and has over [removed: 26] [added: 25] years of experience in the corporate security, crisis management, and security consulting industries, including as head of global security for a major mining company and through leadership positions in several international risk consultancies.

CoreSite’s steering committee includes CoreSite’s Chief Executive Officer, its Chief Accounting Officer, its Chief Revenue Officer, its Senior Vice President of IT & Digitization, its Vice President of Legal, its Senior Vice President of Development & Product Engineering, its Senior Vice President of Data Center Operations, its Senior Vice President of Human Resources, its [removed: Vice President of Compliance & Internal Controls, its] Senior Vice President of Finance & Corporate Development, its Vice President of Information Security and IT Infrastructure, its Director of Compliance & Internal Controls, and American Tower’s CISO.

In [removed: 2024,] [added: 2025,] across our organization, employees completed over [removed: 8,943] [added: 16,000] training classes related to [removed: cybersecurity.][added: cybersecurity and responsible AI use.]

Additionally, in [removed: 2024,] [added: 2025,] to elevate cybersecurity awareness, we also conducted live [removed: training] [added: trainings] as part of our Employee Development program, sent monthly phishing tips to all employees and provided weekly communications during October, which is cybersecurity awareness month.

At least once [removed: per] [added: every other] year, we also engage an outside cybersecurity firm to perform independent [removed: testing.][added: testing or a risk assessment.]

[removed: Our security operations program monitors our] systems and networks, and is responsible for investigating, responding to, and reporting any potential security incidents in a timely manner.

In [removed: 2024,] [added: 2025,] we performed [removed: an IT-focused] [added: a cybersecurity-focused] tabletop exercise which simulated multiple types of cybersecurity incidents, including (a) compromised credentials, (b) brute force attack, (c) uncleaned malware and (d) [removed: ransomware.][added: ransomware to validate and update our internal processes.]

Our Board is responsible for the oversight of our AI strategy and the Audit Committee has oversight over AI-related risk exposure and receives regular AI updates from management.

Our Board, Audit Committee and management have overseen the development and launch of our AI governance program.

Our security operations program monitors our

At the core of our AI governance program is our Global Artificial Intelligence Use and Development Policy, launched in 2025, which establishes the benefits, restrictions and preconditions for AI use and empowers a permanent, cross‑functional AI steering committee to review and approve AI use cases, implement mandatory employee training and ensure that AI is used responsibly and with a balanced assessment of risks and benefits.

Our Chief Technology Officer has over 30 years of experience in the technology space, including leadership roles with wireless carriers

and chip manufacturers, where cybersecurity was critical to the delivery of secure solutions.

As of December 31, [removed: 2024,] [added: 2025,] we owned and operated a portfolio of [removed: 148,957] [added: 149,686] communications sites, including [removed: 860] [added: 862] DAS networks.

[added: In addition, we own property interests that we lease to communications service providers and third-party] tower operators in Canada and the United States, which are included in our U.S. & Canada property segment, and also own and operate data center facilities and related assets in the United States, which are included in our Data Centers segment.

As of December 31, [removed: 2024,] [added: 2025,] the loan underlying the securitization transactions completed in March 2018 and March 2023 (the “2018 Securitization” and the “2023 Securitization”, respectively, and together, the “Trust [removed: Securitizations”)] [added: Securitization”)] is secured by mortgages, deeds of trust and deeds to secure the loan on substantially all of the [removed: 5,029] [added: 5,023] broadcast and wireless communications towers and related assets owned by the borrowers (the “Trust [removed: Sites”) and the secured revenue notes issued in a private transaction completed in May 2015 (the “2015 Securitization”) are secured by mortgages, deeds of trust and deeds to secure debt on substantially all of the 3,338 communications sites owned by subsidiaries of the issuer (the “2015 Secured] Sites”).

*Ground Leases.* Of the [removed: 148,097] [added: 148,824] towers in our portfolio as of December 31, [removed: 2024,] [added: 2025,] approximately 80% were located on land we lease.

As a result, 56% of the ground leases for our sites have a final expiration date of [removed: 2034] [added: 2035] and beyond.

For the year ended December 31, [removed: 2024,] [added: 2025,] our top [removed: three] [added: four] customers by total revenue were T-Mobile [removed: (19%),] [added: (18%),] AT&T [removed: (18%) and] [added: (17%),] Verizon Wireless [removed: (13%).][added: (14%) and Telefónica (10%).]

As a result, approximately [removed: 52%] [added: 48%] of our current tenant leases have a renewal date of [removed: 2030] [added: 2031] or beyond.

*Data Centers.* We own and operate data center facilities and related assets, and as of December 31, [removed: 2024,] [added: 2025,] our data center portfolio consisted of [removed: 29] [added: 30 operating] data center facilities across [removed: ten] [added: eleven] United States markets, across [removed: 3.3] [added: 3.7] million net rentable square feet (“NRSF”).

*Offices.* Our principal corporate headquarters is leased and located in Boston, Massachusetts, where we currently lease approximately [removed: 100,000] [added: 61,000] square feet of office space.

In addition, we own property interests that we lease to communications service providers and third-party

As of February [removed: 18, 2025,] [added: 17, 2026,] we had [removed: 467,457,256] [added: 466,084,820] outstanding shares of common stock and [removed: 127] [added: 121] holders of record.

The performance graph assumes that on December 31, [removed: 2019,] [added: 2020,] $100 was invested in each of our common stock, the S&P 500 Index, the Dow Jones U.S. Telecommunications Equipment Index and the FTSE Nareit All Equity REITs Index.

[removed: ][added: ]

| Dow Jones U.S. Telecommunications Equipment Index | | | | | | 100.00 | | | | | | [removed: 102.32] [added: 145.86] | | | | | | [removed: 149.24] [added: 112.85] | | | | | | [removed: 115.46] [added: 132.91] | | | | | | [removed: 135.99] [added: 185.36] | | | | | | [removed: 189.66] [added: 235.24] | | |

| FTSE Nareit All Equity REITs Index | | | | | | 100.00 | | | | | | [removed: 94.88] [added: 141.30] | | | | | | [removed: 134.06] [added: 106.05] | | | | | | [removed: 100.62] [added: 118.09] | | | | | | [removed: 112.04] [added: 123.90] | | | | | | [removed: 117.56] [added: 126.71] | | |

| | | | | | | 12/20 | | | | | | 12/21 | | | | | | 12/22 | | | | | | 12/23 | | | | | | 12/24 | | | | | | 12/25 | | |

| American Tower Corporation | | | | | | $ | 100.00 | | | | | $ | 132.89 | | | | | $ | 98.83 | | | | | $ | 104.12 | | | | | $ | 91.47 | | | | | $ | 90.61 | |

| S&P 500 Index | | | | | | 100.00 | | | | | | 128.71 | | | | | | 105.40 | | | | | | 133.10 | | | | | | 166.40 | | | | | | 196.16 | | |

Issuer Purchases of Equity Securities

In March 2011, our Board approved a stock repurchase program, pursuant to which we are authorized to repurchase up to $1.5 billion of our common stock (the “2011 Buyback”).

In December 2017, our Board approved an additional stock repurchase program, pursuant to which we are authorized to repurchase up to $2.0 billion of our common stock (the “2017 Buyback,” and together with the 2011 Buyback the “Buyback Programs”).

During the three months ended December 31, 2025, we repurchased a total of 2,036,100 shares of our common stock for an aggregate of $364.6 million, including commissions and fees, pursuant to the 2011 Buyback and the 2017 Buyback.

As of December 31, 2025, we have no amounts remaining under the 2011 Buyback.

The table below sets forth details of our repurchases under the Buyback Programs during the three months ended December 31, 2025.

| | | | | | | | | | | | | | | | | | | | | | | | | | | |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| Period | | | | | | Total Number of Shares Purchased (1) | | | | | | Average Price Paid per Share (2) | | | | | | Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs | | | | | | Approximate Dollar Value of Shares that May Yet be Purchased Under the Plans or Programs (3) | | |

| | | | | | | | | | | | | | | | | | | | | | | | | (in millions) | | |

| October 1, 2025 - October 31, 2025 | | | | | | 240,568 | | | | | | $ | 183.85 | | | | | 240,568 | | | | | | $ | 1,973.4 | |

| November 1, 2025 - November 30, 2025 | | | | | | 705,989 | | | | | | $ | 180.50 | | | | | 705,989 | | | | | | $ | 1,845.9 | |

| December 1, 2025 - December 31, 2025 | | | | | | 1,089,543 | | | | | | $ | 177.08 | | | | | 1,089,543 | | | | | | $ | 1,653.0 | |

| Total Fourth Quarter | | | | | | 2,036,100 | | | | | | $ | 179.07 | | | | | 2,036,100 | | | | | | $ | 1,653.0 | |

_______________

(1) Repurchases made pursuant to the Buyback Programs.

(2) Average price paid per share is a weighted average calculation using the aggregate price, excluding commissions and fees.

(3) Remaining under the 2017 Buyback.

Subsequent to December 31, 2025, through February 17, 2026, we repurchased 312,352 shares of our common stock for an aggregate of approximately $53.0 million, including commissions and fees, under the 2017 Buyback.

Through February 17, 2026, we have repurchased a total of 2,253,664 shares of our common stock under the 2017 Buyback for an aggregate of $400.0 million, including commissions and fees.

We expect to continue to manage the pacing of the remaining $1.6 billion under the 2017 Buyback in response to general market conditions and other relevant factors.

We expect to fund any further repurchases of our common stock through a combination of cash on hand, cash generated by operations and borrowings under our credit facilities.

Purchases under the 2017 Buyback are subject to our having available cash to fund repurchases.

Under the 2017 Buyback, our management is authorized to purchase shares from time to time through open market purchases or in privately negotiated transactions not to exceed market prices and subject to market conditions and other factors.

With respect to open market purchases, we may use plans adopted in accordance with Rule 10b5-1 under the Exchange Act in accordance with securities laws and other legal requirements, which allows us to repurchase shares during periods when we otherwise might be prevented from doing so under insider trading laws or because of self-imposed trading blackout periods.

These programs may be discontinued at any time.

| | | | | | | 12/19 | | | | | | 12/20 | | | | | | 12/21 | | | | | | 12/22 | | | | | | 12/23 | | | | | | 12/24 | | |

| American Tower Corporation | | | | | | $ | 100.00 | | | | | $ | 99.52 | | | | | $ | 132.26 | | | | | $ | 98.36 | | | | | $ | 103.63 | | | | | $ | 91.03 | |

| S&P 500 Index | | | | | | 100.00 | | | | | | 118.40 | | | | | | 152.39 | | | | | | 124.79 | | | | | | 157.59 | | | | | | 197.02 | | |

Based on this evaluation, our principal executive officer and principal financial officer concluded that these disclosure controls and procedures were effective as of December 31, [removed: 2024] [added: 2025] and designed to ensure that the information required to be disclosed in our reports filed or submitted under the Exchange Act is recorded, processed, summarized and reported within the requisite time periods specified in the applicable rules and forms, and that it is accumulated and communicated to our management, including our principal executive officer and principal financial officer, as appropriate, to allow timely decisions regarding required disclosure.

Our management assessed the effectiveness of our internal control over financial reporting as of December 31, [removed: 2024.][added: 2025.]

Based on this assessment, management concluded that, as of December 31, [removed: 2024,] [added: 2025,] our internal control over financial reporting is effective.

There have been no changes in our internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act) during the fiscal quarter ended December 31, [removed: 2024] [added: 2025] that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

We have audited the internal control over financial reporting of American Tower Corporation and subsidiaries (the “Company”) as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in *Internal Control — Integrated Framework (2013)* issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in *Internal Control — Integrated Framework (2013)* issued by COSO.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated financial statements as of and for the year ended December 31, [removed: 2024,] [added: 2025,] of the Company and our report dated February [removed: 25, 2025,] [added: 24, 2026,] expressed an unqualified opinion on those financial statements.

February 24, 2026

February 25, 2025

Ruth T.

Dowling, our Executive Vice President, Chief Administrative Officer, General Counsel and Secretary, entered into a pre-arranged stock trading plan on October 29, 2025.

Ms. Dowling’s plan provides for the potential sale of up to 5,679 shares of our common stock between February 27, 2026 and November 2, 2026.

This trading plan was entered into during an open insider trading window and is intended to satisfy the affirmative defense of Rule 10b5-1 under the Exchange Act and our policies regarding transactions in our securities.

Generally, this trading plan pre-establishes the amounts, prices and dates of future purchases or sales of our stock, including shares issued upon the exercise or vesting of equity awards.

Under this trading plan, the individual officer relinquishes control over the transactions once the trading plan is put into place.

Accordingly, sales under this plan may occur at any time, including possibly before, simultaneously with, or immediately after, significant company events.

None.

Our executive officers and their respective ages and positions as of February [removed: 18, 2025] [added: 17, 2026] are set forth below:

| Steven O. Vondran | | | | | | [removed: 54] [added: 55] | | | | | | President and Chief Executive Officer | | |

| Rodney M. Smith | | | | | | [removed: 59] [added: 60] | | | | | | Executive Vice President, Chief Financial Officer and Treasurer | | |

| Ruth T. Dowling | | | | | | [removed: 55] [added: 56] | | | | | | Executive Vice President, Chief Administrative Officer, General Counsel and Secretary | | |

| Juan A. Font | | | | | | [removed: 56] [added: 57] | | | | | | Senior Vice President, President and CEO, CoreSite | | |

| Robert J. Meyer | | | | | | [removed: 61] [added: 62] | | | | | | Senior Vice President and Chief Accounting Officer | | |

| Eugene M. Noel | | | | | | [removed: 56] [added: 57] | | | | | | Executive Vice President, Chief Operating Officer | | |

| Richard C. Rossi | | | | | | [removed: 49] [added: 50] | | | | | | Executive Vice President and President, U.S. Tower | | |

Mr. Vondran joined us in 2000 as a member of our corporate legal team and served in a variety of positions, including Senior Vice President, U.S. Leasing Operations, Senior Vice President and General Counsel, U.S. Tower Division, Executive Vice [added: President and] President, U.S. Tower Division, and most recently, Executive Vice President and Chief Operating Officer.

Mr. Vondran is a member of the Business [removed: Roundtable.][added: Roundtable and Nareit Executive Board.]

Mr. Vondran [added: also] currently serves on the board of directors of Ameren Corporation.

[removed: He] [added: She] is also [added: the] chair of the board of directors of [removed: ATC Europe.][added: CoreSite.]

Mr. Smith joined us in October 2009, and previously held the roles of Senior Vice President, Corporate [removed: Finance] [added: Finance,] and Treasurer and Senior Vice President and Chief Financial [removed: Officer of American Tower’s] [added: Officer,] U.S. Tower Division.

[removed: She] [added: He] is also a [removed: member of the board of directors] [added: director] of ATC Europe and [removed: of] CoreSite.

Ms. Dowling joined us in [removed: 2011,] [added: 2011] and previously held the roles of Senior Vice President, Corporate Legal, and Senior Vice President and General Counsel for the EMEA and Latin America regions.

Ms. Dowling earned her law degree from Duke University School of Law [added: with high honors] and a Bachelor of Arts from the University of North Carolina Chapel [removed: Hill.][added: Hill with honors.]

Mr. Font received an M.B.A. from The Kogod School of Business at [added: The American University and a Bachelor of Arts in Business Economics and Finance from the Universidad Complutense of Madrid.]

Mr. Noel has more than 25 years of [added: telecommunications real estate development and operations and] network deployment [removed: experience in the telecommunications industry.][added: experience.]

Mr. Rossi serves [removed: on] [added: as] the [added: Vice Chair for WIA’s] board of directors [added: and is a member] of [added: the boards of CTIA and] East Cambridge Savings Bank.

We have adopted an Anti-Insider Trading Policy governing the purchase, sale and/or other dispositions of our securities by our directors, officers, employees and [removed: contractors,] [added: contractors and by the Company,] that we believe is reasonably designed to promote compliance with insider trading laws, rules and regulations and applicable listing standards.

He is also a director of ATC Europe and CoreSite.

Meyer is our Senior Vice President and Chief Accounting Officer and will remain in this role until April 27, 2026, after which he will assist with the transition until his retirement from the Company, which will occur prior to the end of 2026.

He is also a director of ATC Europe and CoreSite.

He is also a director of CoreSite.

| Sanjay Goel | | | | | | 57 | | | | | | Executive Vice President and President, Asia-Pacific | | |

| Olivier Puech | | | | | | 57 | | | | | | Executive Vice President and President, International | | |

He is also a member of the board of directors of ATC Europe.

The American University and a Bachelor of Arts in Business Economics and Finance from the Universidad Complutense of Madrid.

Sanjay Goel is our Executive Vice President and President, Asia-Pacific.

Mr. Goel joined us in March 2021.

Prior to joining us, Mr. Goel was with Nokia, where he started in the mobile networks division in 2001.

During his time at Nokia, he held various sales and business management positions, including Head of the Managed Services Business Line for Asia Pacific, Japan and India and Vice President of the Global Services Business Unit, APAC and Japan.

Mr. Goel also led Nokia’s Global Services business across Asia, the Middle East and Africa, and created a new sales and business development division within Global Services, based in Finland.

Most recently, he served as President of the Global Services business group and Nokia Operations.

Mr. Goel began his career at ABB and IBM, prior to joining Nokia.

He holds a Bachelor’s degree in Engineering with specialization in Electronics and Communications from Manipal Institute of Technology.

Meyer is our Senior Vice President and Chief Accounting Officer.

Mr. Meyer serves as non-executive chair on the board of directors of ATC CSR Foundation in India.

He is also a member of the board of directors of CoreSite.

Olivier Puech is our Executive Vice President and President, International.

Mr. Puech joined us in 2013 as Senior Vice President and CEO of Latin America and served in that role until October 2018 when he was appointed to his current position.

Prior to joining us, Mr. Puech spent 25 years as a senior executive in the telecom and internet sectors of international organizations.

Most recently, he was with Nokia where he held various leadership roles including Senior Vice President Americas, Senior Vice President Asia Pacific and Vice President Latin America.

Before Nokia, Mr. Puech spent 12 years at Gemalto, where he last held the position of Vice President, Sales and Marketing with responsibility for South Europe, Eastern Europe and Latin America.

Mr. Puech holds a Bachelor’s degree in International Business Administration from Ecole Supérieure De Commerce in Marseille, in France.

He is fluent in English, French, Spanish, Italian and Portuguese.

Mr. Rossi also served as the chair for WIA’s Executive Advisory Committee.

| 4.2 | | | | | | [Supplemental Indenture No. [removed: 3,] [added: 4,] dated as of [removed: May 7, 2015,] [added: January 12, 2016,] to Indenture dated as of May 23, 2013, by and between the Company and U.S. Bank National Association, as Trustee, for the [removed: 4.000%] [added: 4.400%] Senior Notes due [removed: 2025](https://www.sec.gov/Archives/edgar/data/1053507/000119312515177193/d924766dex41.htm)] [added: 2026](https://www.sec.gov/Archives/edgar/data/1053507/000119312516427966/d119534dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: May 7, 2015] [added: January 12, 2016] | | | | | | 4.1 | | |

| 4.3 | | | | | | [Supplemental Indenture No. [removed: 4,] [added: 5,] dated as of [removed: January 12,] [added: May 13,] 2016, to Indenture dated as of May 23, 2013, by and between the Company and U.S. Bank National Association, as Trustee, for the [removed: 4.400%] [added: 3.375%] Senior Notes due [removed: 2026](https://www.sec.gov/Archives/edgar/data/1053507/000119312516427966/d119534dex41.htm)] [added: 2026](https://www.sec.gov/Archives/edgar/data/1053507/000105350716000039/ex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: January 12,] [added: May 13,] 2016 | | | | | | 4.1 | | |

| 4.4 | | | | | | [Supplemental Indenture No. [removed: 5,] [added: 6,] dated as of [removed: May 13,] [added: September 30,] 2016, to Indenture dated as of May 23, 2013, by and between the Company and U.S. Bank National Association, as Trustee, for the [removed: 3.375%] [added: 3.125%] Senior Notes due [removed: 2026](https://www.sec.gov/Archives/edgar/data/1053507/000105350716000039/ex41.htm)] [added: 2027](https://www.sec.gov/Archives/edgar/data/1053507/000119312516727705/d278701dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: May 13,] [added: September 30,] 2016 | | | | | | 4.1 | | |

| 4.5 | | | | | | [Supplemental Indenture No. [removed: 6,] [added: 8,] dated as of [removed: September] [added: June] 30, [removed: 2016,] [added: 2017,] to Indenture dated as of May 23, 2013, by and between the Company and U.S. Bank National Association, as Trustee, for the [removed: 3.125%] [added: 3.55%] Senior Notes due [removed: 2027](https://www.sec.gov/Archives/edgar/data/1053507/000119312516727705/d278701dex41.htm)] [added: 2027](https://www.sec.gov/Archives/edgar/data/1053507/000119312517220133/d377927dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: September] [added: June] 30, [removed: 2016] [added: 2017] | | | | | | 4.1 | | |

| [removed: 4.6] [added: 4.7] | | | | | | [Supplemental Indenture No. [removed: 7,] [added: 10,] dated as of [removed: April 6, 2017,] [added: May 22, 2018,] to Indenture dated as of May 23, 2013, by and among the [removed: Company,] [added: Company and] U.S. Bank National Association, as Trustee, and Elavon Financial Services DAC, UK Branch, as Paying Agent, for the [removed: 1.375%] [added: 1.950%] Senior Notes due [removed: 2025](https://www.sec.gov/Archives/edgar/data/1053507/000119312517113618/d373393dex41.htm)] [added: 2026](https://www.sec.gov/Archives/edgar/data/1053507/000119312518170772/d593510dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: April 6, 2017] [added: May 22, 2018] | | | | | | 4.1 | | |

| [removed: 4.7] [added: 4.6] | | | | | | [Supplemental Indenture No. [removed: 8,] [added: 9,] dated as of [removed: June 30,] [added: December 8,] 2017, to Indenture dated as of May 23, 2013, by and between the Company and U.S. Bank National Association, as Trustee, for the [removed: 3.55%] [added: 3.600%] Senior Notes due [removed: 2027](https://www.sec.gov/Archives/edgar/data/1053507/000119312517220133/d377927dex41.htm)] [added: 2028](https://www.sec.gov/Archives/edgar/data/1053507/000119312517364982/d462911dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: June 30,] [added: December 8,] 2017 | | | | | | 4.1 | | |

| 4.8 | | | | | | [Supplemental Indenture No. [removed: 9,] [added: 11,] dated as of [removed: December 8, 2017,] [added: March 15, 2019,] to Indenture dated as of May 23, 2013, by and between the Company and U.S. Bank National Association, as Trustee, for the [removed: 3.600%] [added: 3.950%] Senior Notes due [removed: 2028](https://www.sec.gov/Archives/edgar/data/1053507/000119312517364982/d462911dex41.htm)] [added: 2029](https://www.sec.gov/Archives/edgar/data/1053507/000119312519076792/d723096dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: December 8, 2017] [added: March 15, 2019] | | | | | | 4.1 | | |

| [removed: 4.9] [added: 4.24] | | | | | | [Supplemental Indenture No. [removed: 10,] [added: 2,] dated as of May [removed: 22, 2018,] [added: 16, 2023,] to Indenture dated as of [removed: May 23, 2013,] [added: June 1, 2022] by and among the [removed: Company and] [added: Company,] U.S. Bank [added: Trust Company,] National Association, as Trustee, and Elavon Financial Services DAC, UK Branch, as Paying Agent, for the [removed: 1.950%] [added: 4.125%] Senior Notes due [removed: 2026](https://www.sec.gov/Archives/edgar/data/1053507/000119312518170772/d593510dex41.htm)] [added: 2027 and the 4.625% Senior Notes due 2031](https://www.sec.gov/Archives/edgar/data/1053507/000119312523146124/d482306dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | May [removed: 22, 2018] [added: 16, 2023] | | | | | | 4.1 | | |

| 4.10 | | | | | | [Supplemental Indenture No. [removed: 11,] [added: 1,] dated as of [removed: March 15,] [added: June 13,] 2019, to Indenture dated as of [removed: May 23, 2013,] [added: June 4, 2019,] by and between [removed: the Company] [added: American Tower Corporation] and U.S. Bank National Association, as Trustee, for [removed: the](https://www.sec.gov/Archives/edgar/data/1053507/000119312519076792/d723096dex41.htm) [3.950%] [added: the](https://www.sec.gov/Archives/edgar/data/1053507/000119312519172524/d765969dex41.htm) [3.800%] Senior Notes due [removed: 2029](https://www.sec.gov/Archives/edgar/data/1053507/000119312519076792/d723096dex41.htm)] [added: 2029](https://www.sec.gov/Archives/edgar/data/1053507/000119312519172524/d765969dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: March 15,] [added: June 13,] 2019 | | | | | | 4.1 | | |

| [removed: 4.11] [added: 4.9] | | | | | | [Indenture dated as of June 4, 2019, by and between the Company and U.S. Bank National Association, as Trustee](https://www.sec.gov/Archives/edgar/data/1053507/000119312519164637/d682327dex422.htm) | | | | | | S-3ASR | | | | | | 333-231931 | | | | | | June 4, 2019 | | | | | | 4.22 | | |

| 4.12 | | | | | | [Supplemental Indenture No. [removed: 1,] [added: 3,] dated as of [removed: June 13, 2019,] [added: January 10, 2020,] to Indenture dated as of June 4, 2019, by and between American Tower Corporation and U.S. Bank National Association, as Trustee, for [removed: the 2.950% Senior Notes due 2025 and the 3.800%] [added: the](https://www.sec.gov/Archives/edgar/data/1053507/000119312520005444/d862194dex41.htm) [2.900%] Senior Notes due [removed: 2029](https://www.sec.gov/Archives/edgar/data/1053507/000119312519172524/d765969dex41.htm)] [added: 2030](https://www.sec.gov/Archives/edgar/data/1053507/000119312520005444/d862194dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: June 13, 2019] [added: January 10, 2020] | | | | | | 4.1 | | |

| [removed: 4.13] [added: 4.11] | | | | | | [Supplemental Indenture No. 2, dated as of October 3, 2019, to Indenture dated as of June 4, 2019, by and between American Tower Corporation and U.S. Bank National Association, as Trustee, for the 2.750% Senior Notes due 2027 and the 3.700% Senior Notes due 2049](https://www.sec.gov/Archives/edgar/data/1053507/000119312519261683/d787059dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | October 3, 2019 | | | | | | 4.1 | | |

| [removed: 4.14] [added: 4.15] | | | | | | [Supplemental Indenture No. [removed: 3,] [added: 6,] dated as of [removed: January 10,] [added: September 28,] 2020, to Indenture dated as of June 4, 2019, by and between American Tower Corporation and U.S. Bank National Association, as Trustee, for the [removed: 2.400% Senior Notes due 2025 and the 2.900%] [added: 1.875%] Senior Notes due [removed: 2030](https://www.sec.gov/Archives/edgar/data/1053507/000119312520005444/d862194dex41.htm)] [added: 2030](https://www.sec.gov/Archives/edgar/data/1053507/000119312520256461/d86939dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: January 10,] [added: September 28,] 2020 | | | | | | 4.1 | | |

| [removed: 4.15] [added: 4.13] | | | | | | [Supplemental Indenture No. 4, dated as of June 3, 2020, to Indenture dated as of June 4, 2019, by and between American Tower Corporation and U.S. Bank National Association, as Trustee, for [removed: the 1.300% Senior Notes due 2025, the 2.100%] [added: the](https://www.sec.gov/Archives/edgar/data/1053507/000119312520159551/d918853dex41.htm) [2.100%] Senior Notes due 2030 and the 3.100% Senior Notes due 2050](https://www.sec.gov/Archives/edgar/data/1053507/000119312520159551/d918853dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | June 3, 2020 | | | | | | 4.1 | | |

| [removed: 4.16] [added: 4.14] | | | | | | [Supplemental Indenture No. 5, dated as of September 10, 2020, to Indenture dated as of June 4, 2019, by and among the Company, U.S. Bank National Association, as Trustee, and Elavon Financial Services DAC, UK Branch, as Paying Agent, for the 0.500% Senior Notes due 2028 and the 1.000% Senior Notes due 2032](https://www.sec.gov/Archives/edgar/data/1053507/000119312520243154/d13911dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | September 10, 2020 | | | | | | 4.1 | | |

| 4.17 | | | | | | [Supplemental Indenture No. [removed: 6,] [added: 8,] dated as of [removed: September 28, 2020,] [added: March 29, 2021,] to Indenture dated as of June 4, 2019, by and between American Tower Corporation and U.S. Bank National Association, as Trustee, for the [removed: 1.875%] [added: 1.600%] Senior Notes due [removed: 2030](https://www.sec.gov/Archives/edgar/data/1053507/000119312520256461/d86939dex41.htm)] [added: 2026 and the 2.700% Senior Notes due 2031](https://www.sec.gov/Archives/edgar/data/1053507/000119312521098287/d307128dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: September 28, 2020] [added: March 29, 2021] | | | | | | 4.1 | | |

| [removed: 4.18] [added: 4.16] | | | | | | [Supplemental Indenture No. 7, dated as of November 20, 2020, to Indenture dated as of June 4, 2019, by and between American Tower Corporation and U.S. Bank National Association, as Trustee, for [removed: the](https://www.sec.gov/Archives/edgar/data/1053507/000119312520299409/d14561dex41.htm) [1.500%] [added: the 1.500%] Senior Notes due 2028 and the 2.950% Senior Notes due 2051](https://www.sec.gov/Archives/edgar/data/1053507/000119312520299409/d14561dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | November 20, 2020 | | | | | | 4.1 | | |

| 4.19 | | | | | | [Supplemental Indenture No. [removed: 8,] [added: 10,] dated as of [removed: March 29,] [added: September 27,] 2021, to Indenture dated as of June 4, 2019, by and between American Tower Corporation and U.S. Bank National Association, as Trustee, for the [removed: 1.600%] [added: 1.450%] Senior Notes due 2026 and the [removed: 2.700%] [added: 2.300%] Senior Notes due [removed: 2031](https://www.sec.gov/Archives/edgar/data/1053507/000119312521098287/d307128dex41.htm)] [added: 2031](https://www.sec.gov/Archives/edgar/data/1053507/000119312521284167/d182242dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: March 29,] [added: September 27,] 2021 | | | | | | 4.1 | | |

| [removed: 4.20] [added: 4.18] | | | | | | [Supplemental Indenture No. 9, dated as of May 21, 2021, to Indenture dated as of June 4, 2019, by and among the Company, U.S. Bank National Association, as Trustee, and Elavon Financial Services DAC, UK Branch, as Paying Agent, for the 0.450% Senior Notes due 2027, the 0.875% Senior Notes due 2029 and the 1.250% Senior Notes due 2033](https://www.sec.gov/Archives/edgar/data/1053507/000119312521169283/d186766dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | May 21, 2021 | | | | | | 4.1 | | |

| 4.21 | | | | | | [Supplemental Indenture No. [removed: 10,] [added: 12,] dated as of [removed: September 27, 2021, to] [added: April 1, 2022,](https://www.sec.gov/Archives/edgar/data/1053507/000119312522093656/d313612dex41.htm) [to] Indenture [removed: dated] [added: da](https://www.sec.gov/Archives/edgar/data/1053507/000119312522093656/d313612dex41.htm)[ted] as of June 4, [removed: 2019, by] [added: 2019](https://www.sec.gov/Archives/edgar/data/1053507/000119312522093656/d313612dex41.htm)[,](https://www.sec.gov/Archives/edgar/data/1053507/000119312522093656/d313612dex41.htm) [by] and between American Tower Corporation and U.S. Bank [added: Trust Company,] National Association, as Trustee, for the [removed: 1.450%] [added: 3.650%] Senior Notes due [removed: 2026] [added: 2027] and the [removed: 2.300%] [added: 4.050%] Senior Notes due [removed: 2031](https://www.sec.gov/Archives/edgar/data/1053507/000119312521284167/d182242dex41.htm)] [added: 2032](https://www.sec.gov/Archives/edgar/data/1053507/000119312522093656/d313612dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: September 27, 2021] [added: April 1, 2022] | | | | | | 4.1 | | |

| [removed: 4.22] [added: 4.20] | | | | | | [Supplemental Indenture No. 11, dated as of October 5, 2021, to Indenture dated as of June 4, 2019, by and among the Company, U.S. Bank National Association, as Trustee, and Elavon Financial Services DAC, UK Branch, as Paying Agent, for the 0.400% Senior Notes due 2027 and the 0.950% Senior Notes due 2030](https://www.sec.gov/Archives/edgar/data/1053507/000119312521292090/d208316dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | October 5, 2021 | | | | | | 4.1 | | |

| [removed: 4.23] [added: 4.33] | | | | | | [Supplemental Indenture No. [removed: 12,] [added: 1,] dated as of [removed: April 1, 2022,] [added: December 5, 2025, to Indenture dated as of June 2, 2025,] by and between American Tower Corporation and U.S. Bank Trust Company, National Association, as Trustee, for the [removed: 3.650% Senior Notes due 2027 and the 4.050%] [added: 4.700%] Senior Notes due [removed: 2032](https://www.sec.gov/Archives/edgar/data/1053507/000119312522093656/d313612dex41.htm)] [added: 2032](https://www.sec.gov/Archives/edgar/data/1053507/000119312525309718/d20014dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | [removed: April 1, 2022] [added: December 5, 2025] | | | | | | 4.1 | | |

| [removed: 4.24] [added: 4.22] | | | | | | [Indenture dated as of June 1, 2022, by and between the Company and U.S. Bank Trust Company, National Association, as Trustee](https://www.sec.gov/Archives/edgar/data/1053507/000119312522165192/d468790dex432.htm) | | | | | | S-3ASR | | | | | | 333-265348 | | | | | | June 1, 2022 | | | | | | 4.32 | | |

| [removed: 4.25] [added: 4.23] | | | | | | [Supplemental Indenture No. 1, dated as of March 3, 2023, to Indenture dated as of June 1, 2022, by and between American Tower Corporation and U.S. Bank Trust Company, National Association, as Trustee, for the 5.500% Senior Notes due 2028 and the 5.650% Senior Notes due 2033](https://www.sec.gov/Archives/edgar/data/1053507/000119312523060068/d305272dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | March 3, 2023 | | | | | | 4.1 | | |

| [removed: 4.26] [added: 4.28] | | | | | | [Supplemental Indenture No. [removed: 2,] [added: 6,] dated as of May [removed: 16, 2023,] [added: 29, 2024,] to Indenture dated as of June 1, [removed: 2022] [added: 2022,] by and among the Company, U.S. Bank Trust Company, National Association, as Trustee, and Elavon Financial Services DAC, UK Branch, as Paying Agent, for the [removed: 4.125%] [added: 3.900%] Senior Notes due [removed: 2027] [added: 2030] and the [removed: 4.625%] [added: 4.100%] Senior Notes due [removed: 2031](https://www.sec.gov/Archives/edgar/data/1053507/000119312523146124/d482306dex41.htm)] [added: 2034](https://www.sec.gov/Archives/edgar/data/1053507/000119312524149168/d835521dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | May [removed: 16, 2023] [added: 29, 2024] | | | | | | 4.1 | | |

| [removed: 4.27] [added: 4.25] | | | | | | [Supplemental Indenture No. 3, dated as of May 25, 2023, to Indenture dated as of June 1, 2022, by and between American Tower Corporation and U.S. Bank Trust Company, National Association, as Trustee, for the 5.250% Senior Notes due 2028 and the 5.550% Senior Notes due 2033](https://www.sec.gov/Archives/edgar/data/1053507/000119312523154223/d482735dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | May 25, 2023 | | | | | | 4.1 | | |

| [removed: 4.28] [added: 4.26] | | | | | | [Supplemental Indenture No. 4, dated as of September 15, 2023, to Indenture dated as of June 1, 2022, by and between American Tower Corporation and U.S. Bank Trust Company, National Association, as Trustee, for the 5.800% Senior Notes due 2028 and the 5.900% Senior Notes due 2033](https://www.sec.gov/Archives/edgar/data/1053507/000119312523236155/d481989dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | September 15, 2023 | | | | | | 4.1 | | |

| [removed: 4.29] [added: 4.27] | | | | | | [Supplemental Indenture No. 5, dated as of March 7, 2024, to Indenture dated as of June 1, 2022, by and between the Company and U.S. Bank Trust Company, National Association, as Trustee, for the 5.200% Senior Notes due 2029 and the 5.450% Senior Notes due 2034](https://www.sec.gov/Archives/edgar/data/1053507/000119312524062192/d762865dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | March 7, 2024 | | | | | | 4.1 | | |

| [removed: 4.30] [added: 4.31] | | | | | | [Supplemental Indenture No. [removed: 6,] [added: 9,] dated as of May [removed: 29, 2024,] [added: 30, 2025,] to Indenture dated as of June 1, 2022, by and among the Company, U.S. Bank Trust Company, National Association, as Trustee, and [removed: Elavon Financial Services] [added: U.S. Bank Europe] DAC, UK Branch, as Paying Agent, for the [removed: 3.900%] [added: 3.625%] Senior Notes due [removed: 2030 and the 4.100% Senior Notes due](https://www.sec.gov/Archives/edgar/data/1053507/000119312524149168/d835521dex41.htm) [2034](https://www.sec.gov/Archives/edgar/data/1053507/000119312524149168/d835521dex41.htm)] [added: 2032](https://www.sec.gov/Archives/edgar/data/1053507/000119312525131504/d34761dex41.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | May [removed: 29, 2024] [added: 30, 2025] | | | | | | 4.1 | | |

| [removed: 4.31] [added: 4.29] | | | | | | [Supplemental Indenture No. 7, dated as of November 21, 2024, to Indenture dated as of June 1, 2022, by and between American Tower Corporation and U.S. Bank Trust Company, National Association, as Trustee, for the 5.000% Senior Notes due 2030 and the 5.400% Senior Notes due 2035](https://www.sec.gov/Archives/edgar/data/1053507/000119312524263434/d865445dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | November 21, 2024 | | | | | | 4.1 | | |

| [removed: 4.32] [added: 4.34] | | | | | | [Third Amended and Restated Indenture, dated May 29, 2015, by and between GTP Acquisition Partners I, LLC, ACC Tower Sub, LLC, DCS Tower Sub, LLC, GTP South Acquisitions II, LLC, GTP Acquisition Partners II, LLC, GTP Acquisition Partners, III, LLC, GTP Infrastructure I, LLC, GTP Infrastructure II, LLC, GTP Infrastructure III, LLC, GTP Towers VIII, LLC, GTP Towers I, LLC, GTP Towers II, LLC, GTP Towers IV, LLC, GTP Towers V, LLC, GTP Towers VII, LLC, GTP Towers IX, LLC, PCS Structures Towers, LLC and GTP TRS I LLC, as Obligors, and The Bank of New York Mellon, as Trustee](https://www.sec.gov/Archives/edgar/data/1053507/000119312515268479/d66554dex42.htm) | | | | | | 10-Q | | | | | | 001-14195 | | | | | | July 29, 2015 | | | | | | 4.2 | | |

| [removed: 4.34] [added: 4.35] | | | | | | [Description of Registrant’s [removed: Securities](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit434fy2024.htm)] [added: Securities](https://www.sec.gov/Archives/edgar/data/1053507/000105350726000035/exhibit435fy2025.htm)] | | | | | | Filed herewith as Exhibit [removed: 4.34] [added: 4.35] | | | | | | — | | | | | | — | | | | | | — | | |

| 10.26* | | | | | | [Summary Compensation Information for Current Named Executive [removed: Officers](https://www.sec.gov/Archives/edgar/data/1053507/000105350724000015/amt-20240228.htm)] [added: Officers](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000039/amt-20250227.htm)] | | | | | | 8-K | | | | | | 001-14195 | | | | | | March [removed: 1, 2024] [added: 5, 2025] | | | | | | Item 5.02(e) | | |

| 10.30* | | | | | | [Letter Agreement, dated as of [removed: February 5, 2024,] [added: January 3, 2025,] by and between the Company and [removed: Steven O. Vondran](https://www.sec.gov/Archives/edgar/data/1053507/000105350724000011/exhibit1031fy2023.htm)] [added: Eugene M. Noel](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit1031fy2024.htm)] | | | | | | 10-K | | | | | | 001-14195 | | | | | | February [removed: 27, 2024] [added: 25, 2025] | | | | | | 10.31 | | |

| [removed: 10.31*] [added: 10.32*] | | | | | | [Letter Agreement, dated as of January [removed: 3, 2025,] [added: 2](https://www.sec.gov/Archives/edgar/data/1053507/000105350726000035/exhibit1032fy2025.htm)[6](https://www.sec.gov/Archives/edgar/data/1053507/000105350726000035/exhibit1032fy2025.htm)[, 2026,] by and between the Company and [removed: Eugene M. Noel](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit1031fy2024.htm)] [added: Paul Blanchett](https://www.sec.gov/Archives/edgar/data/1053507/000105350726000035/exhibit1032fy2025.htm)] | | | | | | Filed herewith as Exhibit [removed: 10.31] [added: 10.32] | | | | | | — | | | | | | — | | | | | | — | | |

| [removed: 10.32*] [added: 10.31*] | | | | | | [Letter Agreement, dated as of January 3, 2025, by and between the Company and Richard Rossi](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit1032fy2024.htm) | | | | | | [removed: Filed herewith as Exhibit 10.32] [added: 10-K] | | | | | | [removed: —] [added: 001-14195] | | | | | | [removed: —] [added: February 25, 2025] | | | | | | [removed: —] [added: 10.32] | | |

| 10.36 | | | | | | [Amendment No. 3 to the Third Amended and Restated Multicurrency Revolving Credit Agreement, dated as of January 28, 2025, among the Company and certain of its subsidiaries as borrowers, Toronto Dominion (Texas) LLC, as administrative agent, and a majority of lenders under the Third Amended and Restated Multicurrency Revolving Credit Agreement, dated as of December 8, 2021, as further amended](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit36.htm) | | | | | | [removed: Filed herewith as Exhibit 10.36] [added: 10-K] | | | | | | [removed: —] [added: 001-14195] | | | | | | [removed: —] [added: February 25, 2025] | | | | | | [removed: —] [added: 10.36] | | |

| 10.39 | | | | | | [Amendment No. 2 to the Fourth Amended and Restated Revolving Credit Agreement, dated as of January 28, 2025, among the Company and certain of its subsidiaries as borrowers, Toronto Dominion (Texas) LLC, as administrative agent, and a majority of lenders under the Fourth Amended and Restated Revolving Credit Agreement, dated as of December 8, 2021, as further amended](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit39.htm) | | | | | | [removed: Filed herewith as Exhibit 10.39] [added: 10-K] | | | | | | [removed: —] [added: 001-14195] | | | | | | [removed: —] [added: February 25, 2025] | | | | | | [removed: —] [added: 10.39] | | |

| 10.42 | | | | | | [Amendment No. 2 to the Second Amended and Restated Term Loan Agreement, dated as of January 28, 2025, among the Company, as borrower, Mizuho Bank, Ltd., as administrative agent, and a majority of the lenders under the Second Amended and Restated Term Loan Agreement, dated as of December 8, 2021, as further amended](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit42.htm) | | | | | | [removed: Filed herewith as Exhibit 10.42] [added: 10-K] | | | | | | [removed: —] [added: 001-14195] | | | | | | [removed: —] [added: February 25, 2025] | | | | | | [removed: —] [added: 10.42] | | |

| 19.1 | | | | | | [American Tower Corporation Anti-Insider Trading [removed: Policy](https://www.sec.gov/Archives/edgar/data/1053507/000105350725000025/exhibit191fy2024.htm)] [added: Policy](https://www.sec.gov/Archives/edgar/data/1053507/000105350726000035/exhibit191fy2025.htm)] | | | | | | Filed herewith as Exhibit 19.1 | | | | | | — | | | | | | — | | | | | | — | | |

| 4.30 | | | | | | [Supplemental Indenture No. 8, dated as of March 14, 2025, to Indenture dated as of June 1, 2022, by and between American Tower Corporation and U.S. Bank Trust Company, National Association, as Trustee, for the 4.900% Senior Notes due 2030 and the 5.350% Senior Notes due 2035](https://www.sec.gov/Archives/edgar/data/1053507/000119312525054806/d904653dex41.htm) | | | | | | 8-K | | | | | | 001-14195 | | | | | | March 14, 2025 | | | | | | 4.1 | | |

| 4.32 | | | | | | [Indenture dated as of June 2, 2025, by and between the Company and U.S. Bank Trust Company, National Association, as Trustee](https://www.sec.gov/Archives/edgar/data/1053507/000119312525132847/d948506dex434.htm) | | | | | | S-3ASR | | | | | | 333-287714 | | | | | | June 2, 2025 | | | | | | 4.34 | | |

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| 4.33 | | | | | | [Series 2015-2 Supplement, dated May 29, 2015, to the Third Amended and Restated Indenture dated May 29, 2015](https://www.sec.gov/Archives/edgar/data/1053507/000119312515268479/d66554dex44.htm) | | | | | | 10-Q | | | | | | 001-14195 | | | | | | July 29, 2015 | | | | | | 4.4 | | |

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized on the [removed: 25th] [added: 24th] day of February, [removed: 2025.][added: 2026.]

| /S/ STEVEN O. VONDRAN | | | | | | President and Chief Executive Officer (Principal Executive Officer), Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ RODNEY M. SMITH | | | | | | Executive Vice President, Chief Financial Officer and Treasurer (Principal Financial Officer) | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ ROBERT J. MEYER | | | | | | Senior Vice President and Chief Accounting Officer (Principal Accounting Officer) | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ KELLY C. CHAMBLISS | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ TERESA H. CLARKE | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ KENNETH R. FRANK | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ ROBERT D. HORMATS | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ RAJESH KALATHUR | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ GRACE D. LIEBLEIN | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ CRAIG MACNAB | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ NEVILLE R. RAY | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ PAMELA D. A. REEVE | | | | | | Chair of the Board, Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| /S/ BRUCE L. TANNER | | | | | | Director | | | | | | February [removed: 25, 2025] [added: 24, 2026] | | |

| [Report of Independent Registered Public Accounting [removed: Firm](#i9eb45799c76a40129d05d249625e314b_175)] [added: Firm](#i61f6369049ff4743af4eb2dd4bf56cf3_175)] (PCAOB ID No. 34) | | | | | | [removed: [2](#i9eb45799c76a40129d05d249625e314b_175)] [added: [2](#i61f6369049ff4743af4eb2dd4bf56cf3_175)] | | |

| [Consolidated Balance Sheets as of December 31, [removed: 2024] [added: 2025] and [removed: 2023](#i9eb45799c76a40129d05d249625e314b_178)] [added: 2024](#i61f6369049ff4743af4eb2dd4bf56cf3_178)] | | | | | | [removed: [4](#i9eb45799c76a40129d05d249625e314b_178)] [added: [3](#i61f6369049ff4743af4eb2dd4bf56cf3_178)] | | |

| [Consolidated Statements of Operations for the Years Ended December 31, [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022](#i9eb45799c76a40129d05d249625e314b_181)] [added: 2023](#i61f6369049ff4743af4eb2dd4bf56cf3_181)] | | | | | | [removed: [5](#i9eb45799c76a40129d05d249625e314b_181)] [added: [4](#i61f6369049ff4743af4eb2dd4bf56cf3_181)] | | |

| [Consolidated Statements of Comprehensive Income for the Years Ended December 31, [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022](#i9eb45799c76a40129d05d249625e314b_184)] [added: 2023](#i61f6369049ff4743af4eb2dd4bf56cf3_184)] | | | | | | [removed: [6](#i9eb45799c76a40129d05d249625e314b_184)] [added: [5](#i61f6369049ff4743af4eb2dd4bf56cf3_184)] | | |

| [Consolidated Statements of Equity for the Years Ended December 31, [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022](#i9eb45799c76a40129d05d249625e314b_187)] [added: 2023](#i61f6369049ff4743af4eb2dd4bf56cf3_187)] | | | | | | [removed: [7](#i9eb45799c76a40129d05d249625e314b_187)] [added: [6](#i61f6369049ff4743af4eb2dd4bf56cf3_187)] | | |

| [Consolidated Statements of Cash Flows for the Years Ended December 31, [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022](#i9eb45799c76a40129d05d249625e314b_190)] [added: 2023](#i61f6369049ff4743af4eb2dd4bf56cf3_190)] | | | | | | [removed: [8](#i9eb45799c76a40129d05d249625e314b_190)] [added: [7](#i61f6369049ff4743af4eb2dd4bf56cf3_190)] | | |

| [Notes to Consolidated Financial [removed: Statements](#i9eb45799c76a40129d05d249625e314b_193)] [added: Statements](#i61f6369049ff4743af4eb2dd4bf56cf3_193)] | | | | | | [removed: [9](#i9eb45799c76a40129d05d249625e314b_193)] [added: [8](#i61f6369049ff4743af4eb2dd4bf56cf3_193)] | | |

We have audited the accompanying consolidated balance sheets of American Tower Corporation and subsidiaries (the “Company”) as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] the related consolidated statements of operations, comprehensive income, equity, and cash flows, for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] and the related notes and the schedule listed in the Index at Item 15 (collectively referred to as the “financial statements”).

In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] and the results of its operations and its cash flows for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in *Internal Control — Integrated Framework (2013)* issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February [removed: 25, 2025,] [added: 24, 2026,] expressed an unqualified opinion on the Company's internal control over financial reporting.

[removed: The critical] [added: Critical] audit [removed: matter communicated below is a matter] [added: matters are matters] arising from the current-period audit of the financial statements that [removed: was] [added: were] communicated or required to be communicated to the audit committee and that (1) [removed: relates] [added: relate] to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments.

| | | | | | | December 31, [removed: 2024] [added: 2025] | | | | | | December 31, [removed: 2023] [added: 2024] | | |