ONEOK 10-K 2025-12-31

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-K

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2025.

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from __________ to __________.

Commission file number 001-13643

ONEOK, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (918) 588-7000

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ☐.

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ No ☒.

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☒ Accelerated filer ☐ Non-accelerated filer ☐ Smaller reporting company ☐

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒.

Aggregate market value of registrant’s common stock held by non-affiliates based on the closing trade price on June 30, 2025, was $51.1 billion.

On February 16, 2026, the Company had 629,783,634 shares of common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE:

Portions of the definitive proxy statement to be delivered to shareholders in connection with the Annual Meeting of Shareholders to be held May 20, 2026, are incorporated by reference in Part III.

ONEOK, Inc.

2025 ANNUAL REPORT

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As used in this Annual Report, references to “ONEOK,” “we,” “our,” or “us” refer to ONEOK, Inc., an Oklahoma corporation, and its predecessors and subsidiaries, including Magellan, EnLink and Medallion, unless the context indicates otherwise.

The statements in this Annual Report that are not historical information, including statements concerning plans and objectives of management for future operations, economic performance or related assumptions, are forward-looking statements. Forward-looking statements may include words such as “anticipates,” “believes,” “continues,” “could,” “estimates,” “expects,” “forecasts,” “goal,” “guidance,” “intends,” “may,” “might,” “outlook,” “plans,” “potential,” “projects,” “scheduled,” “should,” “target,” “will,” “would” and other words and terms of similar meaning. Although we believe that our expectations regarding future events are based on reasonable assumptions, we can give no assurance that such expectations or assumptions will be achieved. Important factors that could cause actual results to differ materially from those in the forward-looking statements are described under Part I, Item 1A, Risk Factors.

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GLOSSARY

The abbreviations, acronyms and industry terminology used in this Annual Report are defined as follows:

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PART I

GENERAL

We are incorporated under the laws of the state of Oklahoma, and our common stock is listed on the NYSE under the trading symbol “OKE.” We deliver energy products and services vital to an advancing world. We are a leading midstream service provider of gathering, processing, fractionation, transportation, storage and marine export services. As one of the largest integrated energy infrastructure companies in North America, we are delivering energy that makes a difference in the lives of people in the U.S. and around the world. Through our approximately 60,000-mile pipeline network, we transport the natural gas, NGLs, Refined Products and crude oil that help meet domestic and international energy demand, contribute to energy security and provide safe, reliable and responsible energy solutions needed today and into the future.

Midstream Value Chain

The midstream value chain is a vital part of the energy industry. After crude oil and natural gas are produced from upstream wells, we use our extensive infrastructure to process and transport these raw materials, readying them for end use. For transportation of crude oil, natural gas, Refined Products and NGLs, pipelines are generally the most reliable, lowest cost, least carbon intensive and safest alternative for intermediate and long-haul movements between markets and end users.

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EXECUTIVE SUMMARY

EnLink Acquisition - On January 31, 2025, we completed the EnLink Acquisition. Pursuant to the EnLink Merger Agreement, each publicly held common unit of EnLink was exchanged for a fixed ratio of 0.1412 shares of ONEOK common stock, including EnLink Units that were exchanged for all previously outstanding Series B Preferred Units immediately prior to closing. We issued 41 million shares of common stock with a fair value of $4.0 billion as of the closing date of the EnLink Acquisition. EnLink is now a wholly owned subsidiary.

For additional information on the EnLink Acquisition, see Part II, Item 8, Note B of the Notes to Consolidated Financial Statements in this Annual Report.

Business Update and Market Conditions - Over the past year, we experienced earnings growth across our value chain due primarily to a full year of earnings from EnLink and Medallion across our segments and higher NGL and natural gas processing volumes. Our extensive and integrated assets are located in, and connected with, some of the most productive shale basins, as well as refineries and demand centers, in the United States.

With changes in the commodity price environment, we continue to monitor producers’ drilling and completion plans. Our counterparties are primarily major and independent crude oil and natural gas producers that are able to produce in a lower commodity price environment and continue to find ways to lower costs or enhance production, resulting in profitable projects across our footprint. With our large asset base, multi-basin exposure and continued asset integration, most of our growth opportunities are not contingent on improving commodity prices.

Although the energy industry has experienced many commodity cycles, we have positioned ourselves to reduce exposure to direct commodity price volatility. Each of our four reportable segments are primarily fee-based, and our consolidated earnings were approximately 90% fee-based in 2025.

In addition, our Natural Gas Gathering and Processing and Natural Gas Liquids segments are exposed to volumetric risk as a result of drilling and completion activity, severe weather disruptions, operational outages, global crude oil, NGL and natural gas demand and normal volumetric well declines. Our Refined Products and Crude segment is exposed to volumetric risk due to demand for Refined Products and crude oil in the markets we serve. Our Natural Gas Pipelines segment is not exposed to significant volumetric risk due to the majority of our capacity being subscribed under long-term, firm fee-based contracts.

For additional information regarding the potential impact of volumetric risk on our business, see Item 1A “Risk Factors.”

Capital Allocation - We continue to focus on maintaining prudent financial strength and flexibility. In January 2026, our Board of Directors increased our quarterly dividend to $1.07 per share, an increase of 4% compared with the same quarter in the prior year. In 2024, our Board of Directors authorized a share repurchase program to buy up to $2.0 billion of our outstanding common stock. As of December 31, 2025, we repurchased $234 million of our outstanding common shares under the program. As of December 31, 2025, we also had $78 million of cash and cash equivalents on hand and $3.5 billion of available capacity under our $3.5 Billion Credit Agreement.

Sustainability and Social Responsibility - In 2025, we received an MSCI ESG Rating of AA, and our ESG Risk Rating, as assessed by Morningstar Sustainalytics, was in the top 10% of the refiners and pipelines industry.

Natural Gas Gathering and Processing - In our Natural Gas Gathering and Processing segment, earnings increased in 2025, compared with 2024, due to a full year of earnings from EnLink and higher volumes in the Mid-Continent and Rocky Mountain regions, offset partially by lower realized NGL prices, net of hedging, and the impact from the divestiture of certain nonstrategic assets in 2024. Our 2024 results include the impact of the EnLink Controlling Interest Acquisition from the period of October 15, 2024, to December 31, 2024.

On May 28, 2025, we completed the Delaware Basin JV Acquisition for $941 million. Following the completion of the transaction, it is now a wholly owned subsidiary.

In August 2025, we announced plans to construct the Bighorn natural gas processing plant in the Permian Basin, with processing capacity of 300 MMcf/d and the ability to treat natural gas containing high levels of carbon dioxide. We expect the Bighorn plant, including the carbon dioxide treater, to cost approximately $365 million. The Bighorn plant is supported by acreage dedications with long-term primarily fee-based contracts and is expected to be completed in mid-2027.

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We are also relocating a 150 MMcf/d processing plant to the Permian Basin from North Texas, which will be completed in the first quarter of 2026, and expanding two existing facilities in the Permian Basin, which will provide an incremental 110 MMcf/d of processing capacity and is expected to be completed in the third quarter of 2026.

Natural Gas Liquids - In our Natural Gas Liquids segment, earnings increased in 2025, compared with 2024, due primarily to a full year of earnings from EnLink, higher exchange services and higher optimization and marketing, offset partially by higher operating costs. Our 2024 results include the impact of the EnLink Controlling Interest Acquisition from the period of October 15, 2024, to December 31, 2024.

In 2025, we completed construction of our Elk Creek pipeline expansion project, which increased capacity to 435 MBbl/d and brought our total pipeline capacity out of the Rocky Mountain region to 575 MBbl/d.

In February 2025, we announced definitive agreements to form the Texas City Logistics and MBTC Pipeline joint ventures with MPLX LP to construct a 400 MBbl/d liquified petroleum gas export terminal in Texas City, Texas, and a new 24-inch pipeline from our Mont Belvieu, Texas, storage facility to the new terminal. We expect to invest a total of approximately $1.0 billion into these projects, which a

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You should consider carefully the following discussion of risks, as well as all of the other information contained in this Annual Report. Our business, financial conditions, results of operations or prospects could be materially and adversely affected by any of these risks or uncertainties.

RISK FACTORS RELATED TO OUR BUSINESS AND INDUSTRY

If the level of drilling in the regions in which we operate declines substantially near our assets, our volumes and revenues could decline.

Our gathering and transportation pipeline systems are dependent upon production from natural gas and crude oil wells, which naturally decline over time. As a result, our cash flows associated with these wells may also decline over time. In order to maintain or increase throughput levels on our gathering and transportation pipeline systems and the asset utilization rates at our processing and fractionation facilities, we must continually obtain new supplies. Our ability to maintain or expand our businesses depends largely on the level of drilling and production by third parties in the regions in which we operate. Our natural gas, NGL and crude supply volumes may be impacted if producers curtail or redirect drilling and production activities. Drilling and production are impacted by factors beyond our control, including:

• demand and prices for natural gas, NGLs, Refined Products and crude oil;

• producers’ access to capital;

• producers’ finding and development costs of reserves;

• producers’ ability to secure drilling and completion crews and equipment;

• producers’ desire and ability to obtain necessary permits, drilling rights and surface access in a timely manner and on reasonable terms;

• crude oil and associated natural gas field characteristics and production performance;

• regulatory compliance and environmental or other governmental regulations;

• reserve performance; and

• capacity constraints and/or shutdowns on the pipelines that transport crude oil, natural gas, NGLs and Refined Products from producing areas and our facilities.

Commodity prices are subject to significant volatility. Drilling and production activity levels may vary across our geographic areas; however, a prolonged period of low commodity prices may reduce drilling and production activities across all areas. If we are not able to obtain new supplies to replace the natural decline in volumes from existing production or reductions in volumes because of competition, throughput on our gathering and transportation pipeline systems and the utilization rates of our processing and fractionation facilities would decline, which could adversely affect our business, results of operations, financial position and cash flows.

Our operating results may be adversely affected by unfavorable economic and market conditions.

Uncertainty or adverse changes in economic conditions worldwide, in the United States, or in the economic regions in which we operate, could negatively affect the crude oil and natural gas markets, resulting in reduced demand and increased price competition for our services and products, or otherwise adversely affect our business, results of operations, financial position and cash flows. Volatility in commodity prices may have an impact on many of our suppliers and customers, which, in turn, could have a negative impact on their ability to meet their obligations to us. Periods of severe volatility in equity and credit markets may disrupt our access to such markets, make it difficult to obtain financing necessary to expand facilities or acquire assets, increase financing costs and result in the imposition of restrictive financial covenants. Inflationary pressures have resulted in, and may continue to result in, additional increases to the cost of our materials, services and personnel, which could increase our capital expenditures and operating costs. In addition, future tariffs, trade restrictions or retaliatory measures could further increase our input costs, lengthen delivery schedules or disrupt the availability of key components, particularly if we are unable to manage lead times for materials and equipment used in constructing capital projects or to enter into procurement agreements for long‑lead items to mitigate such risks. Sustained levels of high inflation could cause the Federal Reserve System and other central banks to increase interest rates, which could cause the cost of capital to increase and depress economic growth, either of which, or the combination of both, could adversely affect our business, results of operations, financial position and cash flows.

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The volatility of natural gas, NGL, Refined Products and crude oil prices could adversely affect our earnings and cash flows.

Lower commodity prices could reduce crude oil, natural gas and NGL production, which could decrease the demand for our services. Additionally, a portion of our revenues are derived from the sale of commodities that are received or purchased in conjunction with our gathering, processing, fractionation, transportation and storage services. As commodity prices decline, we could be paid less for our commodities thereby reducing our cash flows. Historically, commodity prices have been volatile and can change quickly. It is likely that commodity prices will continue to be volatile in the future.

The prices we receive for our commodities are subject to wide fluctuations in response to a variety of factors beyond our control, including, but not limited to, the following:

• overall domestic and global economic conditions and uncertainty;

• changes in the supply of, and demand for, domestic and foreign energy, even if relatively minor;

• market uncertainty;

• the occurrence of wars (such as the Russian invasion of Ukraine), the activities of the Organization of Petroleum Exporting Countries (OPEC) and other non-OPEC oil producing countries with large production capacity, or other geopolitical conditions (including instability in the Middle East and Venezuela) impacting supply and demand for natural gas, NGLs, Refined Products and crude oil;

• production decisions by other countries, and the failure of countries to abide by agreements relating to production decisions;

• the availability and cost of third-party transportation, natural gas processing and fractionation capacity;

• the level of consumer product demand and storage inventory levels;

• ethane rejection;

• weather conditions;

• public health crises, including pandemics;

• domestic and foreign governmental regulations and taxes;

• the price and availability of alternative fuels;

• speculation in the commodity futures markets;

• the effects of imports and exports on the price of natural gas, NGLs, Refined Products, crude oil and liquified natural gas;

• the effect of worldwide energy-conservation measures;

• the impact of new supplies, new pipelines, processing and fractionation facilities on location price differentials; and

• technology and improved efficiency impacting supply and demand for natural gas, NGLs, Refined Products and crude oil.

These external factors and the volatile nature of the energy markets make it difficult to reliably estimate future prices of commodities and the impact commodity price fluctuations have on our customers and their need for our services, which could adversely affect our business, results of operations, financial position and cash flows.

Reduced volatility in energy prices or new government regulations could discourage our storage customers from holding positions in Refined Products, crude oil and natural gas, which could adversely affect our business.

The demand for our storage services has resulted in part from customers’ desire to have the ability to take advantage of profit opportunities create

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Not applicable.

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Risk Management and Strategy - We take a cross-disciplinary approach to cybersecurity and physical security. Our annual Enterprise Risk Management (ERM) process encompasses the identification and assessment of a broad range of risks, including cybersecurity, and the development and testing of controls to mitigate these risks. Our ERM assessment is designed to enable our Board of Directors to establish a mutual understanding with management of the effectiveness of our risk-management practices and capabilities, to review our risk exposures and to elevate certain key risks for discussion at the board level. Our ERM program is overseen by our chief financial officer.

Our cybersecurity risk management program is integrated with our ERM program and shares common methodologies, reporting channels and governance processes that apply across the ERM program to other legal compliance, strategic, operational and financial risk areas. Our security program generally incorporates the guidelines of the widely utilized National Institute of Standards and Technology Cybersecurity Framework, though this does not imply we meet any particular technical standards, specifications or requirements. On a regular basis, we engage consultants, including external counsel and cybersecurity firms, to conduct penetration tests and architecture design reviews. In addition, we conduct risk assessments of new enterprise third-party software and cloud vendors by utilizing security questionnaires prior to procurement.

As of February 16, 2026, though the Company and third parties have experienced certain nonmaterial cybersecurity incidents, we are not aware of any cybersecurity threats, that have materially affected or are reasonably likely to materially affect us, including our business strategy, results of operations or financial condition. We face certain ongoing risks from cybersecurity threats that, if realized and material, may materially affect us, including our operations, business strategy, results of operations or financial condition. See Part 1, Item 1A “Risk Factors” for a discussion of risks factors related to cybersecurity.

Governance - Security is governed by the Security Advisory Team, an executive advisory committee composed of company officers, including our chief executive officer, our chief financial officer and our chief enterprise services officer. The Security Advisory Team meets regularly to evaluate ongoing security threats and incidents, to define policy and to prioritize initiatives. Identified cybersecurity threats and incidents are monitored and assessed for materiality by this cross-functional Security Advisory Team. This assessment includes whether our Board of Directors should be informed of a threat or incident. The use of emerging technologies, including the use of Cloud Services and Artificial Intelligence, is governed by our End-User Computing Policy.

The Security Advisory Team is chaired by our vice president of cybersecurity and physical security who has more than twenty years of relevant experience in the field of cyber and physical security. In his role, our vice president of cybersecurity and physical security also supervises efforts to prevent, detect, mitigate and remediate cybersecurity risks and incidents through various means, which include briefings from internal security personnel, alerts and reports produced by security tools deployed in our technology infrastructure and threat intelligence and other information obtained from governmental, public or private sources, including external cybersecurity service providers. Our vice president of cybersecurity and physical security reports to our executive vice president and chief enterprise services officer, responsible for cybersecurity, information technology, enterprise optimization and innovation, among other responsibilities. Before joining ONEOK, our executive vice president and chief enterprise services officer held information technology positions of increasing responsibility.

Cybersecurity risks are communicated and discussed with our Board of Directors at least annually in conjunction with our overall ERM program. Internal Audit provides periodic updates to the Audit Committee on testing completed to meet TSA requirements. As part of its oversight responsibilities, our Board of Directors also receives frequent updates from executive management on our company’s physical and cybersecurity efforts.

A description of our properties is included in Item 1, Business.

We have elected to use a $1 million threshold for disclosing environmental proceedings.

Information about our legal proceedings is included in Note O of the Notes to Consolidated Financial Statements in this Annual Report.

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Not applicable.

PART II

Our common stock is listed on the NYSE under the trading symbol “OKE.” The corporate name ONEOK is used in stock listings.

At February 16, 2026, there were 14,660 holders of record of our 629,783,634 outstanding shares of common stock.

For information regarding our 2025 Employee Stock Award Program and other equity compensation plans, see Note K of the Notes to Consolidated Financial Statements and “Equity Compensation Plan Information” included in Part III, Item 12, Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters, in this Annual Report.

REPURCHASES OF COMMON STOCK

ISSUER PURCHASES OF EQUITY SECURITIES

(a) - In January 2024, our Board of Directors authorized a share repurchase program to buy up to $2.0 billion of our outstanding common stock. The program will terminate upon completion of the repurchases of the $2.0 billion of common stock, or on January 1, 2029, whichever occurs first.

(b) - Shares reported were repurchased in September 2025 and settled in October 2025.

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PERFORMANCE GRAPH

The following performance graph compares the performance of our common stock with the S&P 500 Index, the S&P 500 Energy Index and a ONEOK Peer Group during the period beginning on December 31, 2020, and ending on December 31, 2025.

Value of a $100 Investment, Assuming Reinvestment of Distributions/Dividends,

at December 31, 2020, and at the End of Every Year Through December 31, 2025.

(a) - The S&P 500 Energy Index is a subindex of the S&P 500 that includes those companies classified as members of the energy sector.

(b) - The ONEOK Peer Group in 2025 was composed of the following companies: Antero Midstream Corp.; Energy Transfer LP; Enterprise Products Partners L.P.; Kinder Morgan, Inc.; Kinetik Holdings Inc.; MPLX LP; Plains All American Pipeline, L.P.; Targa Resources Corp.; Western Midstream Partners, LP; and The Williams Companies, Inc.

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The following discussion and analysis should be read in conjunction with Part I, Item 1, Business, our audited Consolidated Financial Statements and the Notes to Consolidated Financial Statements in this Annual Report.

RECENT DEVELOPMENTS

Please refer to the “Financial Results and Operating Information” and “Liquidity and Capital Resources” sections of Management’s Discussion and Analysis of Financial Condition and Results of Operations in this Annual Report for additional information.

Acquisitions

Delaware Basin JV Acquisition - On May 28, 2025, we completed the Delaware Basin JV Acquisition for $941 million. Pursuant to the purchase agreement, we paid $550 million in cash, including post-closing adjustments, which we funded with short-term borrowings and issued approximately 4.9 million shares of ONEOK common stock to the seller with a fair value of $391 million as of the closing date. Following the completion of the transaction, it is now a wholly owned subsidiary.

EnLink Acquisition - On January 31, 2025, we completed the EnLink Acquisition. Pursuant to the EnLink Merger Agreement, each publicly held common unit of EnLink was exchanged for a fixed ratio of 0.1412 shares of ONEOK common stock, including EnLink Units that were exchanged for all previously outstanding Series B Preferred Units immediately prior to closing. We issued 41 million shares of common stock with a fair value of $4.0 billion as of the closing date of the EnLink Acquisition. EnLink is now a wholly owned subsidiary.

For additional information on our most recent acquisitions, see Part II, Item 8, Note B of the Notes to Consolidated Financial Statements in this Annual Report. See Part I, Item 1A “Risk Factors” for further discussion of risks related to these transactions.

Joint Ventures

Eiger Express Pipeline - In 2025, we, WhiteWater, MPLX LP and Enbridge Inc., through the existing Matterhorn joint venture, announced the new approximately 450-mile, 48-inch Eiger Express Pipeline, designed to transport up to approximately 3.7 Bcf/d of natural gas from the Permian Basin to Katy, Texas. WhiteWater will construct and operate the pipeline. Our total ownership interest in the pipeline will be 25.5%, which includes a 15% interest held directly in the Eiger joint venture with the remainder held through Matterhorn. We expect to invest a total of approximately $350 million into this project, which is expected to be completed in mid-2028.

BridgeTex Additional Interest Acquisition - On July 22, 2025, we completed the BridgeTex Additional Interest Acquisition. Pursuant to the purchase agreement, we paid approximately $270 million in cash, which we funded with short-term borrowings. Following the completion of the transaction, we now have a 60% ownership interest in BridgeTex.

Texas City Logistics and MBTC Pipeline - In February 2025, we announced definitive agreements to form joint ventures with MPLX LP to construct a 400 MBbl/d liquified petroleum gas export terminal in Texas City, Texas, and a new 24-inch pipeline from our Mont Belvieu, Texas, storage facility to the new terminal. Texas City Logistics, the export terminal joint venture, is owned 50% by us and 50% by MPLX LP, with MPLX LP constructing and operating the facility. MBTC Pipeline, the pipeline joint venture, is owned 80% by us and 20% by MPLX LP, and we will construct and operate the pipeline. We expect to invest a total of approximately $1.0 billion into these projects, which are expected to be completed in early 2028.

Market Conditions - Earnings increased in 2025, compared with 2024, due primarily to a full year of earnings from EnLink and Medallion across our segments and higher NGL and natural gas processing volumes. Our extensive and integrated assets are located in, and connected with, some of the most productive shale basins, as well as refineries and demand centers, in the United States.

One Big Beautiful Bill Act (OBBBA) - On July 4, 2025, the OBBBA was signed into law. The OBBBA makes changes to U.S. tax law and includes provisions that, beginning in January 2025, make permanent full expensing of tangible personal property and restore EBITDA-based calculations for purposes of the business interest deduction. We expect the OBBBA to reduce our cash taxes beginning with the 2025 tax year; however, we do not anticipate the OBBBA to materially impact net income.

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Capital Projects - Our primary capital projects are outlined in the table below:

(a) - Excludes capitalized interest/AFUDC. For our Texas City Logistics, MBTC Pipeline and Eiger joint venture projects, the amounts presented exclude capital contributions from the other joint venture members.

(b) - This project is expected to be completed in two phases, with the first phase expected to be completed in the fourth quarter of 2026, and the second phase completed in the first quarter of 2027.

(c) - Our investments in Texas City Logistics and Eiger are accounted for using the equity method. Spending on these projects will be recorded as contributions to unconsolidated affiliates.

In our Natural Gas Gathering and Processing segment, we are relocating a 150 MMcf/d processing plant to the Permian Basin from North Texas, which we expect to be completed in the first quarter of 2026.

For a discussion of our capital expenditures financing, see “Capital Expenditures” in the Liquidity and Capital Resources” section.

Debt Issuances - In August 2025, we completed an underwritten public offering of $3.0 billion senior unsecured notes consisting of $750 million, 4.95% senior notes due 2032; $1.0 billion, 5.4% senior notes due 2035; and $1.25 billion, 6.25% senior notes due 2055. The net proceeds, after deducting underwriting discounts, commissions and offering expenses, were $2.96 billion. The net proceeds from this offering were partially used to repay our commercial paper outstanding and repay in full at maturity our senior notes due September 2025. The remaining net proceeds from the offerings were used for general corporate purposes, including the repurchase and redemption of existing notes.

Debt Extinguishments - We completed the following debt extinguishments in 2025:

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Our exposure to market risk, discussed below, includes forward-looking statements and represents an estimate of possible changes in future earnings that could occur assuming hypothetical future movements in interest rates or commodity prices within our derivative portfolio. Our views on market risk are not necessarily indicative of actual results that may occur and do not represent the maximum possible gains and losses that may occur since actual gains and losses will differ from those estimated based on actual fluctuations in interest rates or commodity prices and the timing of transactions.

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We are exposed to market risk due to commodity price and interest-rate volatility. Market risk is the risk of loss arising from adverse changes in market rates and prices. We may use financial instruments, including forward sales, swaps, options and futures, to manage the risks of certain identifiable or anticipated transactions and achieve more predictable cash flows. Our risk-management function follows policies and procedures established by our Risk Oversight and Strategy Committee to monitor our natural gas, NGL, Refined Products, condensate and crude oil marketing activities and interest rates to ensure our hedging activities mitigate market risks and comply with approved thresholds or limits. We do not use financial instruments for trading purposes.

We utilize a sensitivity analysis model to assess the risk associated with our derivative portfolio. The sensitivity analysis measures the potential change in fair value of our derivative instruments based upon a hypothetical 10% movement in the underlying commodity prices or interest rates. In addition to these variables, the fair value of our derivative portfolio is influenced by fluctuations in the notional amounts of the instruments and the discount rates used to determine the present values. Because we enter into these derivative instruments for the purpose of mitigating the risks that accompany certain of our business activities, as described below, the change in the market value of our derivative portfolio would typically be offset largely by a corresponding gain or loss on the hedged item.

See Note A of the Notes to Consolidated Financial Statements in this Annual Report for a discussion on our accounting policies for our derivative instruments and the impact on our Consolidated Financial Statements.

COMMODITY PRICE RISK

As part of our hedging strategy, we use commodity derivative financial instruments and physical-forward contracts described in Note D of the Notes to Consolidated Financial Statements in this Annual Report to reduce the impact of near-term price fluctuations of natural gas, NGLs, Refined Products, condensate and crude oil.

The following table presents the effect a hypothetical 10% change in the underlying commodity prices would have on the estimated fair value of our commodity derivative instruments as of the dates indicated:

Our sensitivity analysis represents an estimate of the reasonably possible gains and losses that would be recognized on our commodity derivative contracts assuming hypothetical movements in future market prices and is not necessarily indicative of actual results that may occur. Actual gains and losses may differ from estimates due to actual fluctuations in market prices, as well as changes in our commodity derivative portfolio during the year.

INTEREST-RATE RISK

We are exposed to interest-rate risk through borrowings under our $3.5 Billion Credit Agreement, commercial paper program and long-term debt issuances. Future increases in commercial paper rates or bond yields could expose us to increased interest costs on future borrowings. We may manage interest-rate risk through the use of fixed-rate debt, floating-rate debt, Treasury locks and interest-rate swaps.

Treasury locks are agreements to pay the difference between the benchmark Treasury rate and the rate that is designated in the terms of the agreement. In the third quarter and second quarter of 2025, we entered into $300 million notional quantity and $700 million notional quantity, respectively, of Treasury locks to hedge the variability of interest payments on a portion of our forecasted debt issuances. In the third quarter of 2025, we settled all of the outstanding $1.0 billion notional quantity of Treasury locks in connection with our underwritten public offering of $3.0 billion senior unsecured notes in August 2025. All of our Treasury locks were designated as cash flow hedges.

At December 31, 2025, and December 31, 2024, we had no outstanding interest-rate derivative instruments.

See Note D of the Notes to Consolidated Financial Statements in this Annual Report for more information on our hedging activities.

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COUNTERPARTY CREDIT RISK

We assess the creditworthiness of our counterparties on an ongoing basis and require security, including prepayments, letters of credit, liens and other forms of collateral, when appropriate. Certain of our counterparties may be impacted by a relatively low commodity price environment and could experience financial problems, which could result in nonpayment and/or nonperformance, which could adversely impact our results of operations. Following our acquisitions in 2024, we now transact with the counterparties of EnLink and Medallion. A substantial portion of EnLink and Medallion counterparties are rated investment-grade by S&P or provide a letter of credit or other collateral.

Natural Gas Gathering and Processing - Our Natural Gas Gathering and Processing segment derives fees for services primarily from major and independent crude oil and natural gas producers, which include both large integrated and independent exploration and production companies. In this segment, our downstream commodity sales customers are primarily utilities, large industrial companies, marketing companies and our NGL affiliate. We are not typically exposed to material credit risk with producers under fee with POP contracts as we sell the commodities and remit a portion of the sales proceeds back to the producer less our contractual fees. In 2025 and 2024, excluding EnLink in 2024, approximately 75% and 85%, respectively, of the downstream commodity sales in our Natural Gas Gathering and Processing segment were made to customers rated investment-grade by S&P, approved through comparable internal counterparty analysis or were secured by letters of credit or other collateral.

Natural Gas Liquids - Our Natural Gas Liquids segment’s counterparties are primarily NGL and natural gas gathering and processing companies; major and independent crude oil and natural gas production companies; utilities; large industrial companies; natural gasoline distributors; propane distributors; municipalities; and petrochemical, refining and marketing companies. We charge fees to NGL and natural gas gathering and processing counterparties and NGL pipeline transportation customers. We are not typically exposed to material credit risk on the majority of our exchange services fees, as we purchase NGLs from our gathering and processing counterparties and deduct our fee from the amounts we remit. We also earn sales revenue on the downstream sales of Purity NGLs. In 2025 and 2024, excluding EnLink in 2024, approximately 95% and 90%, respectively, of this segment’s commodity sales were made to customers rated investment-grade by S&P, approved through comparable internal counterparty analysis or were secured by letters of credit or other collateral. In addition, the majority of our Natural Gas Liquids segment’s pipeline tariffs provide us the ability to require security from shippers.

Natural Gas Pipelines - Our Natural Gas Pipelines segment’s customers are primarily local natural gas distribution companies, electric-generation facilities, large industrial companies, municipalities, producers, processors and marketing companies. In 2025 and 2024, excluding EnLink in 2024, approximately 80% and 90%, respectively, of our revenues in this segment were from customers rated investment-grade by S&P, approved through comparable internal counterparty analysis or were secured by letters of credit or other collateral. In addition, the majority of our pipeline tariffs in this segment provide us the ability to require security from shippers.

Refined Products and Crude - Our Refined Products and Crude segment’s customers include refiners, wholesalers, retailers, traders, railroads, airlines and regional farm cooperatives. In 2025 and 2024, excluding EnLink and Medallion in 2024, approximately 85% and 70%, respectively, of our revenues in this segment were from customers rated investment-grade by S&P, approved through comparable internal counterparty analysis or were secured by letters of credit, liens, or other collateral.

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Report of Independent Registered Public Accounting Firm

To the Board of Directors and Shareholders of ONEOK, Inc.

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheets of ONEOK, Inc. and its subsidiaries (the "Company") as of December 31, 2025 and 2024, and the related consolidated statements of income, of comprehensive income, of equity and of cash flows for each of the three years in the period ended December 31, 2025, including the related notes (collectively referred to as the "consolidated financial statements"). We also have audited the Company's internal control over financial reporting as of December 31, 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 consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

Basis for Opinions

The Company's management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in Management’s Report on Internal Control over Financial Reporting appearing under Item 9A. Our responsibility is to express opinions on the Company’s consolidated financial statements and on the Company's internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects.

Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

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Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Critical Audit Matters

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Revenue Recognition – Liquids Commodity Sales

As described in Note A to the consolidated financial statements, the Company records revenue from liquids commodity sales when the commodity is delivered to the customer as this represents the point in time when control of the product is transferred to the customer. Revenue is recorded based on the contracted selling price, which is generally index-based and settled daily or monthly. The Company recognized liquids commodity sales of $25,566 million for the year ended December 31, 2025.

The principal consideration for our determination that performing procedures relating to revenue recognition for liquids commodity sales is a critical audit matter is a high degree of auditor effort in performing procedures related to the Company’s revenue recognition.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls relating to the revenue recognition process for liquids commodity sales. These procedures also included, among others, (i) testing revenue recognized for a sample of liquids commodity sales revenue transactions by obtaining and inspecting source documents, such as contracts, settlement statements, invoices, and payments receipts and (ii) confirming a sample of outstanding customer invoices balances as of December 31, 2025, and for confirmations not returned, obtaining and inspecting source documents, such as contracts, settlement statements, invoices, and subsequent payment receipt

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FINANCIAL DISCLOSURE

None.

Evaluation of Disclosure Controls and Procedures

Our Chief Executive Officer (Principal Executive Officer) and Chief Financial Officer (Principal Financial Officer) have concluded that our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) of the Exchange Act) were effective as of the end of the period covered by this report.

Management’s Report on Internal Control over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Rule 13a-15(f) and 15d-15(f) of the Exchange Act. Under the supervision and with the participation of our management, including our Principal Executive Officer and Principal Financial Officer, we evaluated the effectiveness of our internal control over financial reporting based on the framework in Internal Control-Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. Because of inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. Based on our evaluation under that framework, our management concluded that our internal control over financial reporting was effective as of December 31, 2025.

The effectiveness of our internal control over financial reporting as of December 31, 2025, has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report which is included herein (Item 8).

Changes in Internal Control over Financial Reporting

There have been no changes in our internal control over financial reporting during the quarter ended December 31, 2025, that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

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During the three months ended December 31, 2025, no director or officer of the Company adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangements,” as each term is defined in item 408(a) Regulation S-K.

Not applicable.

PART III

Directors of the Registrant

Information concerning our directors is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

Executive Officers of the Registrant

Information concerning our executive officers is included in Part I, Item 1, Business, of this Annual Report.

Compliance with Section 16(a) of the Exchange Act

Information on compliance with Section 16(a) of the Exchange Act is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

Code of Ethics

Information concerning the code of ethics, or code of business conduct, is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

Corporate Governance

Information concerning our corporate governance is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

Insider Trading Policy

We have adopted insider trading policies and procedures that govern the purchase, sale and other disposition of our securities by our directors, officers and employees that we believe are reasonably designed to promote compliance with insider trading laws, rules and regulations and the listing standards of the NYSE. A copy of our Insider Trading Policy is filed with this Annual Report as Exhibit 19.

Information on executive compensation is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

Security Ownership of Certain Beneficial Owners

Information concerning the ownership of certain beneficial owners is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

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Security Ownership of Management

Information on security ownership of directors and officers is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

Equity Compensation Plan Information

The following table sets forth certain information concerning our equity compensation plans as of December 31, 2025:

(1) - Included our Employee Stock Purchase Plan, 2025 Employee Stock Award Program, Equity Compensation Plan, 2018 Equity Incentive Plan and 2025 Equity Incentive Plan. For a brief description of the material features of these plans, see Note K of the Notes to Consolidated Financial Statements in this Annual Report.

(2) - Included the assumed EnLink Midstream, LLC, Long-Term Incentive Plan. For a brief description of the material features of this plan, see Note K of the Notes to Consolidated Financial Statements in this Annual Report.

(3) - Included grants of restricted stock unit awards, performance awards and director stock awards deferred as phantom stock units under our Deferred Compensation Plan for Non-Employee Directors.

(4) - There is no exercise price associated with restrictive stock unit awards, performance unit awards or director stock awards as phantom stock units under our Deferred Compensation Plan for Non-Employee Directors.

(5) - Included 969,316, 633,084 and 18,564,569 shares available for future issuance under our Employee Stock Purchase Plan, 2025 Employee Stock Award Program and 2025 Equity Incentive Plan, respectively.

Information on certain relationships and related transactions and director independence is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

Information concerning the principal accountant’s fees and services is set forth in our 2026 definitive Proxy Statement and is incorporated herein by this reference.

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PART IV

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None.

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SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Exchange Act, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Pursuant to the requirements of the Exchange Act, this report has been signed below by the following persons on behalf of the registrant and in the capacities indicated on this 24th day of February 2026.