Ameren (AEE) 10-K risk factor changes: FY2025 vs FY2024

In the planning and management of our operations, we must address the effects of existing and proposed laws and regulations and potential changes in our regulatory frameworks, including [removed: reinterpretation] [added: new interpretations] of [removed: such] [added: existing] regulations, as well [added: as executive orders,] initiatives by federal and state legislatures, RTOs, utility regulators, and taxing authorities, and actions by local jurisdictions that may affect the constructing or siting of facilities.

Significant changes in the nature of the regulation of our businesses, including expiration or discontinuation of, or significant changes to, existing regulatory mechanisms, and the [removed: current federal] [added: presidential] administration’s approach to [removed: United States] [added: environmental and] energy policy and resultant changes in regulatory enforcement priorities, and/or evolving interpretations of existing regulatory requirements, could require changes to our business planning, strategy and management of our businesses and could adversely affect our results of operations, financial position, and liquidity.

Rate orders are also subject to appeal, which creates additional uncertainty as to the rates that we will ultimately be allowed to [removed: charge for our services.]

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[removed: The resulting increase to the revenue requirement needed to recover such costs and earn a return on investments] [added: This] could result in more frequent regulatory rate reviews and requests for cost recovery mechanisms.

[removed: In] [added: Beginning in] 2024 through at least 2027, electric distribution rates for Ameren Illinois are established through an MYRP, which are subject to ongoing regulatory and judicial proceedings and associated risks, and are subject to a reconciliation [removed: cap.][added: cap.]

[removed: The CEJA resulted in changes] [added: Pursuant] to the [removed: regulatory framework applicable to Ameren Illinois’ electric distribution business by giving] [added: CEJA,] Ameren Illinois [added: has] the option to [removed: file an MYRP with the ICC or] establish [added: electric distribution] rates through [added: an MYRP or] a traditional regulatory rate [removed: review, among other things.][added: review.]

Pursuant to [removed: a Missouri law,] [added: the PPRA,] Ameren Missouri’s PISA election was extended through [removed: December 2028] [added: 2035] and an additional extension through [removed: December 2033] [added: 2040] is allowed if requested by Ameren Missouri and approved by the [removed: MoPSC, among other things.][added: MoPSC.]

This law also [removed: established a 2.5%] [added: reduced the] annual limit on increases to the electric service revenue requirement used to set customer rates, compared to the revenue requirement established in the immediately preceding rate order, due to the inclusion of incremental PISA deferrals in the revenue requirement.

Increased capital expenditures could cause incremental PISA deferrals to exceed the [removed: 2.5%] [added: 2.25%] limitation, and such amounts exceeding the [removed: 2.5%] [added: 2.25%] limitation would be excluded from recovery under future revenue requirements.

Failure to limit capital investments to an amount which maintains PISA deferrals under the [removed: 2.5%] [added: 2.25%] limitation could adversely affect Ameren’s and Ameren Missouri’s results of operations, financial position, and liquidity.

Such environmental laws regulate air emissions; protect water bodies; [removed: manage] [added: regulate] the handling and disposal of hazardous substances and waste materials; [added: establish] siting and land use requirements; and [removed: potential] [added: protect against] ecological impacts.

Additionally, the use and handling of various chemicals [removed: or] [added: and] hazardous materials require release prevention plans and emergency response procedures.

Environmental regulations [removed: have a significant] impact [removed: on] the electric utility [removed: industry] [added: industry,] and compliance [removed: with these regulations] [added: obligations] could be costly for Ameren Missouri, which operates coal-fired and natural gas-fired energy centers.

As of December 31, [removed: 2024,] [added: 2025,] Ameren Missouri’s coal-fired energy centers represented [removed: 6%] [added: 5%] and 11% of Ameren’s and Ameren Missouri’s rate base, respectively.

Compliance obligations under the Clean Air Act [removed: include] [added: stem from a variety of programs including] the NSPS, the MATS, emission allowance [removed: programs and] [added: programs,] the CSAPR, and the National Ambient Air Quality Standards, which are subject to periodic review for certain pollutants.

Collectively, these regulations cover a variety of pollutants, such as SO2, particulate matter, NOx, mercury, toxic metals and acid gases, and CO2 [removed: emissions.][added: emissions, although the scope of covered pollutants can change.]

[removed: Regulations implementing] [added: To] the [removed: Clean Water Act govern potential impacts from] [added: extent] our operations [removed: on] [added: impact surface] water [removed: bodies] [added: bodies,] including [removed: wetlands subject to] [added: wetlands,] the [removed: Act,] [added: Clean Water Act requires permitting] as well as evaluation of the ecological and biological impact of those operations.

Implementation of [added: requirements under] the Clean Air Act and the Clean Water Act [removed: requirements] typically occurs through the issuance of permits by state regulators or resource agencies, and capital expenditures associated with compliance could be significant.

[removed: Coal-fired energy centers must comply with] [added: The] management and disposal [removed: requirements for] [added: of] coal ash [added: from our coal-fired energy centers must comply with federal regulations known as the CCR Rule issued] under the Resource Conservation and Recovery Act and [removed: federal regulations known as] [added: require] the [removed: CCR Rule.][added: closure of surface impoundments at our coal-fired energy centers along with groundwater monitoring requirements and the implementations of corrective measures if necessary.]

The [removed: individual or] combined effects of compliance with existing and [removed: new] [added: future] environmental regulations could result in significant capital expenditures, increased operating costs, [removed: or] [added: and] the [added: potential for] closure or alteration of operations at some of Ameren Missouri’s energy centers.

Further reductions to emissions limits will become effective between 2030 and 2040, resulting in the [added: possible] closure of the Venice Energy Center by the end of 2029.

The reductions could also limit the operations of Ameren Missouri's four other natural gas-fired energy centers located in the state of [removed: Illinois,] [added: Illinois] and will result in their closure by 2040.

We are subject to business and financial risks related to the impact of [removed: climate change] [added: climate-related] legislation, regulation, and emission reduction initiatives.

There is concern and activism among various external stakeholders, both nationally and internationally, about [removed: climate change,] [added: climate-related risks,] including public concerns about the potential environmental impacts from the combustion of fossil fuels, as well as pressure from public interest groups regarding limiting the use of natural gas.

Further, federal, state, and local [removed: authorities, including the United States Congress,] [added: authorities] have considered initiatives to further restrict greenhouse gases to address global [removed: climate change, and the EPA previously announced plans to implement new climate change programs, including regulation of greenhouse gas emissions from the utility industry.][added: climate-related risks.]

The [removed: current federal administration is expected to review, and] [added: EPA] has [removed: already] revised, [added: and has proposed revisions to,] compliance requirements under a number of federal environmental regulatory [removed: programs;] [added: programs related to greenhouse gases;] however, differences in energy policy priorities adopted by future [removed: federal] [added: presidential] administrations could result in additional greenhouse gas reduction requirements in the United States.

Excessive costs to comply with future legislation or regulations related to [removed: climate change] [added: climate-related risks] might force Ameren Missouri to close its remaining coal-fired energy centers earlier than planned, which could lead to possible loss on abandonment and reduced revenues.

Achievement of these targets is dependent on many factors, including the pace and extent of development and deployment of low- to zero-carbon energy technologies and carbon capture technologies, the cost of those technologies, and support of such technologies by regulators; natural gas [added: and energy] prices; [added: operational performance of low- to zero-carbon resources;] new transmission infrastructure; the ability to maintain system [removed: reliability during and after the transition to clean] [added: reliability; customer demand for] energy [removed: generation;] [added: including carbon-free energy;] and constructive energy and economic policies, including those that address investment in energy infrastructure, global [removed: climate change,] [added: climate-related risks,] incentives for clean energy technologies, and environmental regulations.

The strategy to achieve these goals also relies on continuing to pursue a diverse portfolio, including low-carbon and carbon-free resources and energy-efficiency [removed: resources;] [added: resources, while still meeting load growth opportunities;] continuing to participate in efforts to help advance the development of technologies such as carbon capture and sequestration; the use of hydrogen fuel for electric production and energy storage, next generation nuclear, and large-scale long-cycle battery [removed: energy] storage; and constructively engaging with legislators, regulators, investors, customers, and other stakeholders to support outcomes leading to a net-zero future.

We are subject to FERC regulations, rules, and orders, including standards [removed: required] [added: issued] by the NERC.

We may also incur higher operating costs to comply with potential new executive orders, regulations, or [removed: reinterpretations] [added: interpretations] of existing regulations issued by these regulatory bodies.

We estimate that we will invest up to [removed: $27.4] [added: $33.1] billion (Ameren Missouri – up to [removed: $17.5] [added: $22.2] billion; Ameren Illinois – up to [removed: $7.0] [added: $8.3] billion; ATXI – up to [removed: $2.9] [added: $2.6] billion) of capital expenditures from [removed: 2025] [added: 2026] through [removed: 2029.][added: 2030.]

These factors include, but are not limited to, the following: project management expertise; the ability of suppliers, contractors, and developers to meet contractual commitments and timely complete projects, which is dependent upon the availability of necessary labor, materials, and equipment; escalating costs, including but not limited to changes to tariffs on materials or government actions; changes in the scope and timing of projects; the ability to obtain required regulatory, project, and permit approvals; the ability to obtain necessary rights-of-way, easements, and transmission connection agreements at an acceptable cost in a timely fashion; unsatisfactory performance by the projects when completed; the [removed: inability to earn an adequate return on invested capital; the] ability to raise capital on reasonable terms; geopolitical conflict and other events beyond our control, including delays arising from government shutdowns or construction delays due to weather.

With respect to the transition of Ameren Missouri’s generation fleet [removed: that will be] included in its 2025 Change to the 2023 PRP and carbon emission reduction targets, factors also include Ameren Missouri’s ability to obtain CCNs from the MoPSC, and any other required [added: state or federal] approvals for the addition of renewable resources, battery storage, or nuclear or natural gas-fired generation, retirement of energy centers, and new or continued customer energy-efficiency programs; the ability to enter into agreements for renewable, natural gas-fired, or nuclear generation [added: or battery storage] and acquire or construct [removed: that generation] [added: those resources] at a reasonable cost; the ability to [added: enter into natural gas supply agreements at reasonable prices and adequate quantities to power Ameren Missouri’s natural gas-fired energy centers; the ability to] obtain NRC approval for an extension of the operating license for the Callaway Energy Center beyond its current 2044 expiration date; the continued existence and ability to qualify for, and use or transfer, federal production or investment tax credits; the [removed: cost of wind, solar, and other renewable generation and battery storage technologies; the cost of natural gas or hydrogen CT technologies; the cost of nuclear generation; the] ability to maintain system [removed: reliability during and after the transition to clean energy generation;] [added: reliability;] new and/or changes in environmental regulations, including those related to CO2 and other greenhouse gas emissions; energy prices; and demand.

- inability to maintain reliability of our electric utility services as coal-fired energy centers are retired and renewable energy generation is placed in service, as well as our ability to meet generation capacity [removed: obligations;][added: obligations, which could potentially increase if new data centers and/or other large primary service customers locate within our service territories;]

- disruptions to the global supply chain as a result of shortages for labor, materials, or equipment, tariffs and international trade relations, geopolitical conflict, delivery delays, and economic pressures, [removed: including elevated interest rates and inflation,] among other things;

- unusual or adverse weather conditions or other natural disasters, including but not limited to those that may result from [removed: climate change,] [added: climate-related risks,] such as severe storms, droughts, wildfires, floods, tornadoes, earthquakes, icing, sustained high or low temperatures, solar flares, and electromagnetic pulses;

- inability to operate wind generation facilities at full capacity resulting from requirements to protect natural resources, including wildlife, or other conditions limiting full [removed: capacity, such as the 2024 collapse of three turbines at the High Prairie Energy Center; pending the results of an ongoing investigation, approximately 90% of the turbines of the High Prairie Energy Center remain idle and the timing and costs necessary to return the energy center to full capacity are uncertain;][added: capacity;]

- the occurrence of catastrophic events such as fires, explosions, acts of sabotage, which [added: in recent years] have increased in frequency and severity within the utility industry, acts of terrorism, civil unrest, pandemic health events, or other similar events;

charge for our services.

Pursuant to the PPRA, Ameren Missouri’s natural gas utility rates established in proceedings filed after June 2026 will be allowed to be based on future costs, revenues, and sales volumes, subject to MoPSC approval.

Ameren Missouri and Ameren Illinois, and the utility industry generally, have experienced higher maintenance costs and capital expenditures to operate their electric, natural gas, and transmission businesses, which has led to increases in customer rates and the related revenue requirements needed to recover such costs and earn a return on investments.

The annual limit in effect was 2.5% and changed to 2.25%, prorated monthly, for revenue requirements approved by the MoPSC after August 2025.

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The United States withdrew from the Paris Agreement and the United Nations Framework Convention on Climate Change in January 2025 and 2026, respectively.

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Also, changes to capacity accreditation rules adopted by the MISO could reduce the accredited capacity of renewable generation and battery storage and increase regional capacity prices, potentially requiring additional investment and higher costs to satisfy resource adequacy requirements.

In addition, the presidential administration has issued executive orders and taken other actions to increase investment in fossil fuel infrastructure.

This change in federal domestic energy policy has created uncertainty regarding the role existing renewable generation will play in supporting the United States’ energy grid and the timing and extent of future renewable generation infrastructure development.

Ameren Missouri’s plan could be affected by this change in energy policy.

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- increased regulatory scrutiny and oversight resulting from more frequent outages;

Realized energy demand from current and potential new customers may differ significantly from forecasts.

In addition, in February 2026, Ameren Missouri executed electric service agreements with large load customers under its large load customer rate plan, representing 2.2 gigawatts of demand.

Also, demand growth may not be realized at the rate, or in the amount, expected if construction of customer facilities is not completed within expected timeframes, which is dependent on the ability of suppliers, contractors, and developers to meet contractual commitments and timely complete projects.

In addition, expected demand growth may not be realized if emerging technologies are not broadly adopted at the rate expected, increased efficiencies in computing or other advances in these technologies reduce energy demand for data centers, or large load customers, such as data centers,

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are not supported by local communities or do not receive necessary approvals by local municipalities.

Although customers subject to the large load customer rate plan in Ameren Missouri’s service territory are required to sign agreements for specific term lengths to reasonably ensure rates they are charged reflect a representative share of the costs incurred to serve them, these customers could terminate their agreements early or reduce minimum capacity levels.

These agreements include exit fees for early termination and fees for capacity reductions, but these fees may not fully mitigate this risk.

Although assets constructed or acquired to serve these customers will also be used to serve other Ameren Missouri customers, early termination or capacity reductions could impact Ameren Missouri’s ability to fully recover its investment in, and return on, those assets.

In addition, demand for construction services within the utility industry has increased significantly due to growing energy demand and energy transition, creating limited availability of suppliers, contractors, and developers, which could impact the Ameren Companies' ability to timely construct or acquire assets needed to meet forecasted demand.

If the Ameren Companies are required to purchase energy and capacity to meet demand, their risk management and liquidity levels may not be effective at mitigating price impacts of such purchases, or there may not be sufficient energy and capacity available, either of which could negatively impact the Ameren Companies’ ability to realize forecasted or other potential demand.

- technological advancements that reduce energy consumption and demand;

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In addition, rising energy and capacity prices, which are largely outside of our control, could impact customer affordability and satisfaction.

Ameren Missouri’s and Ameren Illinois’ recent electric and natural gas regulatory rate reviews have resulted in increases in rates charged to customers which had an adverse impact on customer satisfaction and increased political pressures and media attention.

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Ameren Missouri and Ameren Illinois expect to renew these contracts prior to their expiration, however there can be no guarantee that such renewals will be secured on favorable terms.

This also includes attacks arising from or generated by artificial intelligence, among various other attempts to compromise systems that can lead to security breaches.

These factors include depressed economic conditions, a recession, increasing interest rates, inflation, sanctions, trade restrictions, tariffs or trade wars, government or federal agency shutdowns, political

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Ameren Missouri and Ameren Illinois, and the utility industry generally, have an increased need for cost recovery and to earn a return on investments, primarily driven by capital investments, which is likely to continue in the future.

In addition, in June 2024, the MoPSC issued a financing order authorizing the issuance of securitized utility tariff bonds by a wholly owned, special purpose subsidiary of Ameren Missouri to finance approximately $476 million of costs related to the accelerated retirement of the Rush Island Energy Center, which included the remaining unrecovered net plant balance associated with the facility, among other costs.

Ameren Missouri will collect the amounts necessary to repay the bonds over approximately 15 years from the date of bond issuance.

The securitized tariff bonds were issued in December 2024.

The financing order also included a determination that the decision to retire the Rush Island Energy Center was reasonable and prudent.

The MoPSC did not make a determination regarding the prudency of Ameren Missouri's prior actions that resulted in the adverse ruling in the NSR and Clean Air Act litigation discussed in Note 14 – Commitments and Contingencies under Part II, Item 8, of this report, however, claims regarding such actions could be considered in future regulatory proceedings.

If future regulatory proceedings result in revenue reductions based on Ameren Missouri’s prior actions that resulted in the adverse ruling in the NSR and Clean Air Act litigation, it could have a material adverse effect on the results of operations, financial position, and liquidity of Ameren and Ameren Missouri.

Additionally, Ameren Illinois is subject to certain performance metrics that if not achieved would result in a reduction to the company’s allowed ROE.

Ameren Illinois’ electric distribution service business is also subject to performance metrics.

Failure to achieve the metrics would result in a reduction in the company’s allowed ROE calculated under the MYRP.

In 2022, the ICC issued an order approving total ROE incentives and penalties of 24 basis points under the MYRP, allocated among seven performance metrics.

These performance metrics include improvements in service reliability in both the frequency and duration of outages, a reduction in peak loads, an increased percentage of

spend with diverse suppliers, a reduction in disconnections for certain customers, and improved timeliness in response to customer requests for interconnection of distributed energy resources.

These performance metrics apply annually from 2024 through 2027 under the MYRP, and the impact of any incentives and penalties will be excluded from the reconciliation cap described above.

In addition, the allowed ROE on energy-efficiency investments can be increased or decreased up to 200 basis points, depending on the achievement of annual energy savings goals.

Any adjustments to the allowed ROE for energy-efficiency investments will depend on annual performance for a historical period relative to energy savings goals.

The limitation is effective for revenue requirements approved by the MoPSC after January 1, 2024.

Surface impoundments at Ameren Missouri’s coal-fired energy centers are subject to closure and groundwater monitoring requirements and the implementations of corrective measures if necessary.

In April 2024, the EPA issued a final rule that sets CO2 emission standards for existing coal-fired and new natural gas-fired power plants based on the emissions expected from adoption of carbon capture technology and/or natural gas co-firing for coal-fired power plants and

carbon capture technology for new natural gas-fired power plants.

Affected power plants are required to comply with the rule through a phased-in approach or retire.

Compliance with the new rule could be required as early as 2030 for certain existing coal-fired power plants and 2032 for certain new natural gas-fired power plants.

In December 2024, the United States Court of Appeals for the District of Columbia Circuit heard arguments from various stakeholders including the EPA, environmental organizations, state attorney generals, and industry groups regarding the legal merits of the final rule.

In February 2025, the EPA requested that the appellate court suspend the case for 60 days and not issue an opinion so the EPA can decide how to proceed.

Ameren and Ameren Missouri estimate capital expenditures of approximately $580 million may be necessary to comply with the final rule assuming it is not revised or overturned.

Ameren and Ameren Missouri are monitoring the legal challenges and assessing the impacts of the final rule and, at this time, cannot predict the final impacts on their results of operations, financial position, and liquidity.

In accordance with the new presidential administration’s approach to United States energy policy, in January 2025, the United States withdrew from the Paris Agreement.

maintenance expense.

Forecasted energy demand from potential new customers and electrification might not be realized.

Future demand from these customers may not be realized at the current projected pace as a result of increased efficiency in computing, and these new customers may be transitory and exit our service territory.

Significant uncertainty exists regarding future increases in energy demand within the Ameren Companies’ service territory, and whether and how the Ameren Companies will construct or obtain the assets necessary to timely serve that additional demand.

The payments related to the minimum tax by Ameren

increased use of distributed generation by our customers.

These factors include depressed economic conditions, a recession,

Discussion regarding our financial condition and results of operations for the year ended December 31, [removed: 2022,] [added: 2023,] including comparisons with the year ended December 31, [removed: 2023,] [added: 2024,] is included in Item 7 of our Form 10-K for the year ended December 31, [removed: 2023.][added: 2024.]

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Our core strategy is driven by the following three pillars, which allow us to [removed: capitalize] [added: deliver] on opportunities to benefit our customers, communities, [removed: shareholders,] and [removed: the environment:][added: shareholders:]

| To [removed: capitalize] [added: deliver] on opportunities to benefit our customers, communities, [removed: shareholders,] and [removed: the environment] [added: shareholders] | | | | | | | | | | | | | | | | | | | | |

| Rate Base ($ in billions)(a) | | | | | | | | | Regulatory Frameworks(c) | | | | | | | | | Electric Customer [removed: Rates(f)] [added: Rates(g)] | | |

| ] [added: Chart.jpg](https://www.sec.gov/Archives/edgar/data/1002910/000100291026000009/aee-20251231_g6.jpg)] | | | | | | | | | Segment | | | Regulatory Framework | | | | | | ] [added: Rates for print.jpg](https://www.sec.gov/Archives/edgar/data/1002910/000100291026000009/aee-20251231_g7.jpg)] | | |

| | | | Ameren Illinois Natural Gas | | | *Future test year ratemaking and PGA and VBA Allowed ROE of [removed: 9.44%*] [added: 9.60%*] | | | | | | | | | | | | | | |

| | | | Ameren Missouri | | | *Historical test year [removed: ratemaking and PISA,] [added: ratemaking(f)* *and* *PISA,] RESRAM, FAC, MEEIA, [removed: PGA Allowed] [added: PGA* *Allowed] ROE is not specified* | | | | | | | | | | | | | | |

| (a)Reflects year-end rate base except for Ameren Transmission, which is average rate base. Ameren Illinois Electric Distribution excludes electric energy-efficiency rate base. (b)Compound annual growth rate. (c)As of January [removed: 2025.] [added: 2026.] (d)Ameren Illinois filed appeals of the December [removed: 2023 and] [added: 2023,] June [removed: 2024 orders,] [added: 2024,] and [removed: intends to file an appeal of the] December 2024 [removed: ICC order,] [added: orders] in its MYRP proceeding. For more information on the MYRP proceeding, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report. [removed: (e)Ameren] [added: (e)Through 2026, Ameren] Illinois’ formula ratemaking framework related to energy-efficiency investments uses an allowed ROE of the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points, subject to performance standards discussed in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report. [removed: (f)Average] [added: (f)Pursuant to the PPRA, Ameren Missouri will be allowed to use a future test year, subject to MoPSC approval, to set natural gas delivery service rates beginning in July 2026. For more information on the PPRA, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report. (g)Average] residential electric [removed: prices.] [added: prices in cents per kilowatthour.] Source: Edison Electric Institute, ‘Typical Bills and Average Rates Report’ for the 12 months ended June 30, [removed: 2024.] [added: 2025.] | | | | | | | | | | | | | | | | | | | | |

In [removed: June] [added: comparison, in] 2024, [removed: the MoPSC issued a financing order authorizing] [added: Ameren utilized net proceeds of $2.5 billion from] the issuance of [removed: securitized utility tariff bonds by AMF] [added: long-term debt for capital expenditures,] to [removed: finance $476] [added: repay then-outstanding short-term debt, to repay $49] million of [added: maturities of long-term debt at ATXI, and to finance energy transition] costs related to the accelerated retirement of the Rush Island Energy Center, which included the remaining unrecovered net plant balance associated with the facility, among other costs.

In February [removed: 2025,] [added: 2026,] Ameren Missouri filed an update to its Smart Energy Plan with the MoPSC, which includes a five-year capital investment overview with a detailed one-year plan for [removed: 2025.][added: 2026.]

Investments under the plan are expected to total approximately [removed: $16.2] [added: $20.8] billion over the five-year period from [removed: 2025] [added: 2026] through [removed: 2029,] [added: 2030,] with expenditures largely recoverable under the PISA.

See Note 14 – Commitments and Contingencies under Part II, Item 8, of this report, for additional information on [removed: the EPA regulations.][added: environmental matters.]

In November [removed: 2023,] [added: 2025,] the ICC issued an order in Ameren Illinois’ January [removed: 2023] [added: 2025] natural gas delivery service regulatory rate review, which resulted in an increase to its annual revenues for natural gas delivery service of [removed: $112] [added: $79] million based on a [removed: 9.44% allowed] [added: 9.60%] ROE, a capital structure composed of 50% common equity, [added: a 2026 future test year,] and a rate base of [removed: approximately $2.85] [added: $3.2] billion.

The order reflected a reduction of [removed: approximately $93] [added: $75] million of planned distribution and transmission capital investments included in Ameren Illinois’ [removed: requested revenue increase, which used a 2024] future test [removed: year.][added: year request.]

The new rates became effective [removed: on November 28, 2023.][added: December 2025.]

In January [removed: 2024, the ICC denied Ameren Illinois’ rehearing request, and] [added: 2026,] Ameren Illinois filed an appeal [removed: with] [added: of] the [added: ICC’s November 2025 order and the ICC’s January 2026 order rejecting Ameren Illinois’ rehearing request to the] Illinois Appellate Court for the Fifth Judicial District.

In December [removed: 2023,] [added: 2024,] the ICC issued an order in [removed: Ameren Illinois'] [added: connection with a revised Grid Plan and a revised] MYRP [removed: proceeding] [added: filed by Ameren Illinois in March 2024,] approving [removed: base rates] [added: revenue requirements] for electric distribution services for 2024 through 2027 [removed: and rejecting Ameren Illinois' Grid Plan, which was addressed as part] of [removed: the MYRP proceeding.][added: $1,206 million, $1,287 million, $1,367 million, and $1,421 million, respectively.]

In [removed: June 2024,] [added: December 2025,] the ICC issued an order [removed: on] [added: approving] Ameren Illinois’ [removed: rehearing request approving revenue requirements for] [added: 2024] electric distribution [removed: services for 2024 through 2027.][added: service revenue requirement reconciliation adjustment filing.]

In [removed: July 2024, Ameren Illinois filed a request for rehearing of] [added: February 2026,] the [removed: ICC’s June 2024] [added: ICC denied Ameren Illinois’] rehearing [removed: order] [added: request] to include an asset associated with other postretirement benefits in the rate [removed: base.][added: base, among other things.]

[removed: Also, in January 2024,] [added: In March 2025,] Ameren Illinois filed an appeal of the [added: ICC’s] December [removed: 2023 ICC order, including the 8.72% ROE, and subsequently updated the appeal filing in September] 2024 [added: order] to [removed: include] the [removed: June 2024 rehearing order regarding] [added: Illinois Appellate Court for] the [removed: inclusion of] [added: Fifth Judicial District to revise the allowed ROE and to include] an asset associated with other postretirement benefits in the rate [removed: base to the Illinois Appellate Court for the Fifth Judicial District.][added: base, among other things.]

The court is under no deadline to address the [removed: appeal] [added: appeal,] and Ameren Illinois cannot predict the ultimate outcome of the appeal.

[removed: In March] [added: *•*In December] 2024, [removed: pursuant to] the [removed: December 2023] ICC [added: issued an] order [removed: discussed above, Ameren Illinois filed] [added: in connection with] a revised Grid Plan and a revised MYRP [removed: to update the requested] [added: filed by Ameren Illinois in March 2024, approving] revenue requirements for [added: electric distribution services for] 2024 through [removed: 2027.][added: 2027 of $1,206 million, $1,287 million, $1,367 million, and $1,421 million, respectively.]

In [removed: January] [added: March] 2025, Ameren Illinois filed [removed: a request for rehearing] [added: an appeal] of the ICC’s December 2024 order to [added: the Illinois Appellate Court for the Fifth Judicial District to] revise the allowed ROE and to include an asset associated with other postretirement benefits in the rate base, among other things.

[added: In January 2026,] Ameren Illinois [removed: intends to file] [added: filed] an appeal of the ICC’s [removed: December 2024] [added: November 2025] order and [removed: update] the [removed: appeal filed in September 2024] [added: ICC’s January 2026 order rejecting Ameren Illinois’ rehearing request] to the Illinois Appellate Court for the Fifth Judicial [removed: District as discussed above.][added: District.]

In November [removed: 2024,] [added: 2025,] the ICC issued an order in Ameren Illinois’ annual update filing that approved [added: an] electric customer energy-efficiency [removed: rates] [added: revenue requirement] of [removed: $126] [added: $138] million beginning in January [removed: 2025,] [added: 2026,] which represents an increase of [removed: $26] [added: $12] million from [removed: 2024 rates.][added: the 2025 revenue requirement.]

This order was based on a projected [removed: 2025] [added: 2026] year-end rate base of [removed: $434] [added: $474] million.

In December [removed: 2024,] [added: 2025,] the ICC issued an order approving Ameren Illinois’ [removed: 2023] [added: 2024] electric distribution service revenue requirement reconciliation adjustment filing.

This order approved [removed: a reconciliation] [added: an] adjustment [removed: of $158] [added: increasing the allowed revenue requirement by $48] million, which reflected Ameren Illinois’ actual [removed: 2023] [added: 2024] recoverable costs, year-end rate base of $4.2 billion, and capital structure composed of 50% common equity.

The approved reconciliation adjustment will be collected from customers in [removed: 2025.][added: 2026.]

[added: -] In [removed: January] [added: November] 2025, [removed: Ameren Illinois filed a request with] the ICC [removed: seeking approval to] [added: issued an order in Ameren Illinois’ January 2025 natural gas delivery service regulatory rate review, which resulted in an] increase [added: to] its annual revenues for natural gas delivery service [removed: by $140] [added: of $79] million.

Related to these projects, Ameren began substation upgrades in [removed: May] 2024 in advance of transmission line construction, which is expected to begin in [added: spring] 2026, with forecasted completion dates near the end of this decade.

Also in [removed: December] 2024, the MISO approved a first set of second tranche projects.

The [removed: first set of second tranche projects also includes] [added: remaining] competitive bid projects that [added: have not been awarded] are estimated to cost [removed: $6.5] [added: $4.4] billion, which includes projects located in Illinois that are estimated to cost [removed: $1.8] [added: $1.7] billion, based on the MISO’s cost estimate.

The competitive bid process is expected to [removed: take place] [added: continue] through 2026.

[removed: In October 2024,] [added: -] the [added: absence of the October 2024] FERC [removed: issued an order, which decreased] [added: order reducing] the allowed base ROE for [removed: FERC-regulated] [added: FERC regulated] transmission rate base [removed: under the MISO tariff from 10.02% to 9.98%] and required [removed: refunds, with interest,] [added: refunds] for [removed: the] [added: certain prior] periods [removed: from November 2013 to February 2015] [added: under the MISO tariff, which increased Ameren Transmission earnings (4 cents per share);] and [removed: from late September 2016 forward.]

In February [removed: 2024,] [added: 2026,] Ameren’s board of directors increased the quarterly common stock dividend to [removed: 67] [added: 75] cents per share, resulting in an annualized equivalent dividend rate of [removed: $2.68] [added: $3.00] per share.

Net income attributable to Ameren common shareholders was [removed: $1,182] [added: $1,456] million, or [removed: $4.42] [added: $5.35] per diluted share, for [removed: 2024,] [added: 2025,] and [removed: $1,152] [added: $1,182] million, or [removed: $4.38] [added: $4.42] per diluted share, for [removed: 2023.][added: 2024.]

Net income was [removed: also] favorably affected in [removed: 2024,] [added: 2025,] compared with [removed: 2023,] [added: 2024,] by increased base rate revenues [added: at Ameren Missouri effective June 1, 2025,] pursuant to the [removed: MoPSC's June 2023] [added: April 2025 MoPSC] electric rate order [removed: as well as higher base rate revenues pursuant to the ICC's November 2023 natural gas rate order, which increased earnings] [added: and decreased tax expense] at Ameren [added: Transmission, Ameren] Illinois [added: Electric Distribution and Ameren Illinois] Natural [removed: Gas.][added: Gas due to the revaluation of excess deferred income tax regulatory liabilities.]

At December 31, [removed: 2024,] [added: 2025,] Ameren, on a consolidated basis, had available liquidity in the form of cash on hand and amounts available under the Credit Agreements of [removed: $1.4] [added: $2.5] billion.

The PPRA became effective in August 2025.

The law includes certain provisions that affect the regulation of Ameren Missouri’s electric and natural gas businesses.

These provisions create modifications to the PISA and integrated resource planning, require electric utilities to submit service tariff schedules for certain large load customers, allow the MoPSC to authorize inclusion of construction work in progress in rate base for new natural gas-fired generation facilities and new generation facilities approved through integrated resource planning, and allow natural gas utilities to file regulatory rate reviews using a future test year, among other things.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

In April 2025, the MoPSC issued an order in Ameren Missouri’s 2024 electric service regulatory rate review, approving nonunanimous stipulations and agreements.

The order authorized an increase of $355 million to Ameren Missouri’s annual revenue requirement for electric retail service, effective June 1, 2025.

The approved revenue requirement was based on infrastructure investments as of December 31, 2024.

The order did not explicitly specify an ROE, capital structure, rate base, or any rate base disallowances.

The order provides for the continued use of all existing riders and trackers.

The order also changed annualized depreciation, regulatory asset and liability amortization amounts, and the base level of expenses for trackers.

On an annualized basis, these changes reflect an increase in “Depreciation and amortization” of approximately $70 million, among other expense changes, on Ameren’s and Ameren Missouri’s consolidated statements of income.

In July 2025, the MoPSC issued an order in Ameren Missouri’s 2024 natural gas delivery service regulatory rate review, approving a unanimous stipulation and agreement.

The order authorized an increase of $32 million to Ameren Missouri’s annual revenue requirement for natural gas delivery service, effective September 1, 2025.

The order did not explicitly specify an ROE, capital structure, rate base, or any rate base disallowances.

The order provides for the continued use of all of Ameren Missouri’s existing riders and trackers.

In November 2025, the MoPSC approved Ameren Missouri’s request to modify its existing large primary service tariff to require customers requesting 75 MWs or more of demand and who are served at transmission level voltage to comply with additional tariff terms.

The additional terms include a service term of 12 years plus a ramp period of up to five years to reach peak demand, minimum demand charges of 80% of contracted capacity, customer exit terms and fees, and customer credit and collateral requirements, among other terms.

In addition, new customer programs would be available under this tariff, which allow customers to support renewable generation, battery storage, and/or nuclear generation through incremental payments.

The MoPSC order also includes an earnings sharing mechanism that would apply if Ameren Missouri’s earned ROE for a calendar year exceeds 9.74%, which can be adjusted by the MoPSC in future electric rate orders.

If this were to occur, Ameren Missouri would defer 65% of the return in excess of the 9.74% ROE to a regulatory liability, which would be returned to retail electric customers in a future rate review.

In addition, if large load customer revenues were reduced in a calendar year due to certain events, as determined by the MoPSC, Ameren Missouri may defer a portion of the reduced revenues to a regulatory asset to be included in its revenue requirement in the next electric rate review.

In February 2026, Ameren Missouri executed electric service agreements with large load customers consistent with the tariff terms discussed above, representing 2.2 gigawatts of demand.

Ameren and Ameren Missouri do not expect a material impact to their results of operations, financial position, or liquidity in 2026 related to these agreements.

In August 2025, Ameren Missouri filed for a CCN to construct the Reform Solar Project (250-MW facility).

Ameren Missouri expects a decision by the MoPSC in the first half of 2026.

In February 2026, the MoPSC issued an order approving a nonunanimous stipulation and agreement related to a requested CCN for the Big Hollow Natural Gas (800-MW facility) and the Big Hollow Battery Energy Storage (400-MW facility) projects.

Also in February 2026, Ameren Missouri acquired the Split Rail Solar Project, which includes solar panels, project design, land rights, and engineering, procurement, and construction agreements, for approximately $600 million, and took over construction management of the project, which is expected to be placed in-service in the second quarter of 2026.

The appellate court is under no deadline to address the appeals.

Ameren Illinois is assessing whether to pursue an appeal with the Illinois Appellate Court for the Fifth Judicial District in the first half of 2026.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

In August 2025, the ICC issued an order approving Ameren Illinois’ energy-efficiency plan that includes annual investments in electric energy-efficiency programs of approximately $126 million per year from 2026 through 2029.

The ICC has the ability to reduce the amount of electric energy-efficiency savings goals in future program years if there are insufficient cost-effective programs available, which could reduce the investments in electric energy-efficiency programs.

In January 2026, the CRGA was enacted and will become effective in June 2026.

The law includes certain provisions that affect Ameren Illinois’ electric distribution and transmission businesses.

These provisions increase the annual spending cap on energy-efficiency investments beginning in 2027 and modify the ROE component of the return on those investments.

The appeal challenged the inclusion of the non-service cost component of the net periodic benefit income related to other postretirement benefits in the annual revenue requirement and the $75 million reduction of planned capital investments, among other things.

The court is under no deadline to address the appeal.

Earnings were also favorably affected by increased retail electric sales volumes at Ameren Missouri, primarily due to warmer July temperatures and colder winter temperatures in 2025, and by decreased other operations and maintenance expenses not subject to formula rates, riders, or trackers, because of the absence in 2025 of an Ameren Missouri charge related to the resolution of outstanding claims in the NSR and Clean Air Act litigation associated with the Rush Island Energy Center.

Additionally, earnings were favorably affected by the increased deferral of financing costs related to rate base investments at Ameren Missouri and by increased infrastructure investments at Ameren Transmission and Ameren Illinois Electric Distribution.

Net income was unfavorably affected in 2025 compared with 2024 by increased financing costs, primarily resulting from higher interest rates on higher debt balances at Ameren Missouri and Ameren (parent) and by increased other operations and maintenance expenses not subject to formula rates, riders, or trackers, excluding a charge related to the NSR and Clean Air Act litigation, primarily due to higher vegetation management costs, higher storm costs, and higher energy center maintenance expenses.

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

In September 2023, the United States District Court for the Eastern District of Missouri granted Ameren Missouri’s request to modify a September 2019 remedy order issued by the district court in order to allow the retirement of the Rush Island Energy Center in advance of its previously expected retirement date of 2039, in lieu of installing a flue gas desulfurization system.

Ameren Missouri retired the Rush Island Energy Center on October 15, 2024.

In December 2024, the United States District Court for the Eastern District of Missouri issued an order resolving all outstanding claims in this case.

The order requires Ameren Missouri to fund a program to provide electric buses and charging stations to schools in the metro St. Louis area and a program to provide air purifiers to eligible Ameren Missouri electric residential customers.

These programs are estimated to cost approximately $64 million.

As of December 31, 2024, Ameren and Ameren Missouri recorded liabilities of $64 million and charges of $59 million in 2024 related to the cost of these programs.

In June 2024, Ameren Missouri filed a request with the MoPSC seeking approval to increase its annual revenues for electric service.

In February 2025, Ameren Missouri filed an updated electric rate increase request seeking approval to increase its annual revenues for electric service by $446 million.

The electric rate increase request is based on a 10.25% ROE, a capital structure composed of 52% common equity, a rate base of $13.9 billion, and a test year ended March 31, 2024, with certain pro-forma adjustments through the true-up date of December 31, 2024.

In February 2025, the MoPSC staff recommended an increase to Ameren Missouri's annual electric service revenues of $384 million based on a 9.74% ROE, a capital structure composed of 52% common equity, and a rate base of $13.9 billion.

The MoPSC proceeding relating to the proposed electric service rate changes will take place over a period of up to 11 months, with a decision by the MoPSC expected by May 2025 and new rates effective by June 2025.

Ameren Missouri will collect the amounts necessary to repay the bonds over approximately 15 years from the date of bond issuance.

The securitized tariff bonds were issued in December 2024.

The financing order also included a determination that the decision to retire the Rush Island Energy Center was reasonable and prudent.

The MoPSC did not make a determination regarding the prudency of Ameren Missouri's prior actions that resulted in the adverse ruling in the NSR and Clean Air Act litigation discussed in Note 14 – Commitments and Contingencies under Part II, Item 8, of this report, however, claims regarding such actions could be considered in future regulatory proceedings.

If future regulatory proceedings result in revenue reductions based on Ameren Missouri’s prior actions that resulted in the adverse ruling in the NSR and Clean Air Act litigation, it could have a material adverse effect on the results of operations, financial position, and liquidity of Ameren and Ameren Missouri.

In 2024, the MoPSC issued orders approving requested CCNs for the Split Rail, Vandalia, Bowling Green, and Cass County solar projects.

Ameren Missouri acquired the Cass County, Boomtown, and Huck Finn solar projects in June 2024, September 2024, and October 2024, respectively, and placed the assets of the projects, totaling $1 billion, in service in December 2024.

In October 2024, the MoPSC issued an order approving a nonunanimous stipulation and agreement filed by Ameren Missouri, the MoPSC staff, and other intervenors requesting a CCN for the Castle Bluff Natural Gas Project.

The order also includes the use of a post-construction cost deferral related to the project, which allows Ameren Missouri to defer and recover depreciation expense, financing costs, and applicable income taxes incurred from the date the project is placed in service to the date when project costs are reflected in updated base rates as a result of a regulatory rate review.

The period of deferral would be limited to the earlier of the time the project costs are reflected in base rates or six months.

In September 2024, Ameren Missouri filed a request with the MoPSC seeking approval to increase its annual revenues for natural gas delivery service by $40 million.

The natural gas rate increase request is based on a 10.25% ROE, a capital structure composed of 52% common equity, a rate base of $531 million, and a test year ended March 31, 2024, with certain pro-forma adjustments expected through the true-up date of December 31, 2024.

The MoPSC proceeding relating to the proposed natural gas delivery service rate changes will take place over a period of up to 11 months, with a decision by the MoPSC expected by August 2025 and new rates effective by September 2025.

In November 2024, the MoPSC issued an order approving a nonunanimous stipulation and agreement for Ameren Missouri’s MEEIA 2025 plan, which includes a portfolio of customer energy-efficiency and demand response programs, along with the continued use of the MEEIA rider, which allows Ameren Missouri to collect from customers its actual MEEIA program costs, related lost electric revenues, and performance incentives.

Ameren Missouri intends to invest $51 million annually in 2025 and 2026 and $22 million in 2027 for customer energy-efficiency and demand response programs.

In addition, the order approved performance incentives applicable to each plan year to earn revenues by achieving certain spending and demand response goals.

If 100% of the goals are achieved in 2025, 2026, and 2027, Ameren Missouri would earn performance incentive revenues of $5 million, $5 million, and $2 million, respectively.

Ameren Missouri’s Smart Energy Plan includes approximately $1 billion in capital expenditures that may be necessary to comply with regulations issued by the EPA in 2024 relating to CO2 emissions and MATS, if such regulations are not revised or overturned.

In December 2023, Ameren Illinois filed a request for rehearing of the ICC's November 2023 order.

The filing requested the ICC revise the order to include an allowed ROE of at least 9.89%, a capital structure composed of 52% common equity, and a reversal of the approximately $93 million reduction of planned distribution and

transmission capital investments included in the order, among other things.

In January 2025, the appellate court ruled on the appeal filed by Ameren Illinois.

In that ruling, the court reversed a reduction of planned transmission capital investments of $48 million, but affirmed the ICC-approved 9.44% ROE and the remaining reduction of planned distribution capital investments.

Ameren Illinois took prudent steps to align its operations with the ICC order, while continuing to ensure safe and adequate service is maintained.

Rate changes consistent with the December 2023 order became effective in January 2024 and remained effective through late June 2024, when new rates became effective pursuant to the June 2024 ICC rehearing order discussed below.

The December 2023 order adopted an alternative methodology to establish a rate base and revenue requirements for the years 2024 through 2027 using Ameren Illinois’ previously approved 2022 year-end rate base.

In January 2024, the ICC partially denied a rehearing requested by Ameren Illinois to revise the allowed ROE in the December 2023 order and granted Ameren Illinois’ rehearing request to reconsider the rate base for each year of the MYRP and to include a base level of investments to maintain grid reliability in each year of the MYRP.

New rates became effective in late June 2024 and remained effective through late December 2024, when new rates became effective pursuant to the December 2024 ICC order discussed below.

We manage our interest rate exposure by controlling the amount of debt instruments within our total capitalization portfolio, by monitoring the effects of market changes on interest rates, and by entering into interest rate swaps to hedge a portion of our interest rate risk on cash flows related to [added: certain] forecasted debt issuances.

The estimated increase in our annual interest expense and decrease in net income if interest rates were to increase by 100 basis points on variable-rate debt outstanding at December 31, [removed: 2024] [added: 2025] is immaterial.

[removed: The] [added: Through 2026, the] allowed ROE under Ameren Illinois’ electric energy-efficiency investments formula ratemaking recovery mechanisms is based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points.

See Note 7 – Derivative Financial Instruments under Part II, Item 8, of this report for information on the potential loss on counterparty exposure as of December 31, [removed: 2024.][added: 2025.]

At December 31, [removed: 2024,] [added: 2025,] no nonaffiliated customer represented more than 10% of our accounts receivable.

When that option is selected, Ameren Illinois produces consolidated bills for the applicable retail customers to reflect charges for electric distribution and purchased receivables from the alternative retail electric [removed: suppler.][added: supplier.]

As of December 31, [removed: 2024,] [added: 2025,] Ameren Illinois’ balance of purchased accounts receivable associated with the utility consolidated billing and purchase of receivables services was [removed: $43] [added: $47] million.

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

Contributions to the plans and future costs could increase materially if we do not achieve pension and postretirement asset portfolio investment returns equal to or in excess of our [removed: 2025] [added: 2026] assumed return on plan assets of 6.75%.

As of December 31, [removed: 2024,] [added: 2025,] this fund was invested in domestic equity securities [removed: (68%)] [added: (67%)] and debt securities [removed: (31%).][added: (32%).]

Additionally, Ameren and Ameren Illinois have COLI contracts with net cash surrender values of [removed: $150] [added: $102] million and [removed: $8] [added: $9] million, respectively, as of December 31, [removed: 2024.][added: 2025.]

As of December 31, [removed: 2024,] [added: 2025,] that separate account is comprised of approximately [removed: 50%] [added: 40%] equity securities and [removed: 50%] [added: 60%] debt securities.

In [removed: 2024,] [added: 2025,] Ameren Illinois procured power on behalf of its customers for [removed: 25%] [added: 28%] of its total kilowatthour sales.

[removed: Ameren Illinois has purchased approximately 14% of] its [removed: summer 2025, 9% of its fall 2025, none of its] winter [removed: 2025/26] [added: 2026/27] and [removed: 2%] [added: 61%] of its spring [removed: 2026] [added: 2027] capacity needs bilaterally, however, this percentage beyond May [removed: 2026] [added: 2027] will be dependent on the results of future IPA procurement events.

[added: Through the IPA's] development and filing of the [removed: 2025] [added: 2026] Electricity Procurement Plan, the ICC has approved the plan's proposal for multiple IPA procurement events over the following year.

These events will procure portions of Ameren Illinois' energy and capacity forecasted requirements for forward delivery years through May [removed: 2028.][added: 2029.]

Ameren Illinois has also entered into ICC-approved contracts for zero emission credits through May 2027 and for renewable energy credits with various terms, including contracts with 20-year terms ending 2032, and contracts entered into beginning in 2018 through [removed: 2024] [added: 2025] with 15- to 20-year terms.

The following table presents, as of December 31, [removed: 2024,] [added: 2025,] the percentages of the projected required supply of coal and coal transportation for Ameren Missouri’s coal-fired energy centers, nuclear fuel for Ameren Missouri’s Callaway Energy Center, natural gas for Ameren Missouri’s and Ameren Illinois’ retail distribution, and purchased power for Ameren Illinois that are price-hedged over the period [removed: 2025] [added: 2026] through [removed: 2029.][added: 2030.]

| Coal(a) | | | [removed: 93] [added: 98] | | % | | | | [removed: 73] [added: 76] | | % | | | | [removed: 47] [added: 49] | | % |

| Coal transportation(a) | | | [removed: 99] [added: 100] | | | | | | [removed: 99] [added: 96] | | | | | | 96 | | |

| Natural gas for distribution(b) | | | [removed: 100] [added: 92] | | | | | | [removed: 50] [added: 49] | | | | | | [removed: 26] [added: 28] | | |

| Natural gas for distribution(b) | | | [removed: 91] [added: 75] | | | | | | [removed: 52] [added: 46] | | | | | | [removed: 25] [added: 22] | | |

| Natural gas for distribution(b) | | | [removed: 100] [added: 96] | | % | | | | 49 | | % | | | | [removed: 27] [added: 29] | | % |

The year [removed: 2025] [added: 2026] represents January [removed: 2025] [added: 2026] through March [removed: 2025.][added: 2026.]

The year [removed: 2026] [added: 2027] represents November [removed: 2025] [added: 2026] through March [removed: 2026.][added: 2027.]

This continues each successive year through March [removed: 2029.][added: 2030.]

Ameren Missouri has agreements with multiple suppliers to purchase low-sulfur coal through [removed: 2029] [added: 2030] to comply with environmental regulations.

Current industry projections reflect the potential for significant growth in energy demand over the next decade, primarily arising from data centers and further augmented by onshoring and electrification of manufacturing and an increase in transportation electrification.

This projected growth could create volatility for the prices of purchased power and capacity.

Ameren Illinois has purchased approximately 55% of its summer 2026, 46% of its fall 2026, 40% of

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

Pursuant to Illinois law, Ameren Illinois is required to enter into these contracts to comply with Illinois’ renewable energy and zero emission standards.

These contracts, with the exception of certain contracts entered into in 2010, do not serve to meet Ameren Illinois’ energy and capacity needs.

| | | | 2026 | | | | | | 2027 | | | | | | 2028 – 2030 | | |

| Coal(a) | | | 98 | | % | | | | 76 | | % | | | | 49 | | % |

| Coal transportation(a) | | | 100 | | | | | | 96 | | | | | | 96 | | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

Through the IPA's

| | | | 2025 | | | | | | 2026 | | | | | | 2027 – 2029 | | |

Also see Note 14 – Commitments and Contingencies under Part II, Item 8, of this report for additional information.

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

[removed: An illustration of the Ameren Companies’ reporting structures is provided below:][added: ]

(b) [removed: The] [added: Through 2025, the] Ameren Transmission segment also [removed: includes] [added: included] allocated Ameren (parent) interest charges, as well as other subsidiaries engaged in electric transmission project development and investment.

The following table summarizes the key terms of the rate orders in effect for customer billings for each of Ameren’s utilities as of January 1, [removed: 2025,] [added: 2026,] except as noted:

| | | | Rate Regulator | | | Effective Rate Order Issued In | | | Rates Effective | | | Allowed ROE | | | Percent of Common Equity | | | Rate Base (in billions) | | | Portion of Ameren’s [removed: 2024] [added: 2025] Operating Revenues(a) | | |

| Electric service(b) | | | MoPSC | | | [removed: June 2023] [added: April 2025] | | | [removed: July 2023] [added: June 2025] | | | (c) | | | (c) | | | (c) | | | [removed: 50%] [added: 52%] | | |

| Electric distribution delivery [removed: service(e)] [added: service(d)] | | | ICC | | | December 2024 | | | [removed: (e)] [added: (d)] | | | 8.72% | | | 50.00% | | | [removed: (e)] [added: (d)] | | | [removed: 27%] [added: 26%] | | |

| Natural gas delivery service(f) | | | ICC | | | November [removed: 2023] [added: 2025] | | | [removed: November 2023] [added: December 2025] | | | [removed: 9.44%] [added: 9.60%] | | | 50.00% | | | [removed: $2.8] [added: $3.2] | | | [removed: 12%] [added: 11%] | | |

| Electric transmission service(g) | | | FERC | | | (g) | | | January [removed: 2025] [added: 2026] | | | 10.48% | | | [removed: 54.91%] [added: 54.98%] | | | [removed: $4.4] [added: $4.6] | | | 6% | | |

| Electric transmission service(g) | | | FERC | | | (g) | | | January [removed: 2025] [added: 2026] | | | 10.48% | | | [removed: 60.08%] [added: 60.02%] | | | [removed: $1.6] [added: $1.8] | | | [removed: 3%] [added: 2%] | | |

[removed: The order] [added: (d)In December 2024, the ICC] approved an average annual rate base for 2024, 2025, 2026, and 2027 of $4.2 billion, $4.4 billion, $4.6 billion, and $4.8 billion, respectively.

Rate changes consistent with the December [removed: 2024] [added: 2025 reconciliation] order became effective in [removed: late December 2024.][added: January 2026.]

Under [removed: an] [added: the] MYRP, Ameren Illinois [removed: will reconcile] [added: reconciles] its actual revenue requirement, as adjusted for certain cost variations, to ICC-approved electric distribution service rates on an annual basis, subject to a reconciliation cap.

(f)This rate order was based on a [removed: 2024] [added: 2026] future test year.

The SERC is one of six regional entities and represents all or portions of 16 central and southeastern states under authority from the [removed: NERC for the purpose of implementing and enforcing reliability standards approved by the FERC.][added: NERC.]

The regional entities of the NERC [removed: work] [added: implement and enforce reliability standards approved by the FERC] to safeguard the reliability of the bulk power systems throughout North America.

The license for the Callaway Energy Center [removed: expires] [added: is currently set to expire] in 2044.

Ameren Missouri’s Keokuk Energy Center and its dam on the Mississippi River between Hamilton, Illinois, and Keokuk, Iowa, [added: are operated under authority granted by an Act of Congress in 1905.]

Our electric generation, transmission, and distribution and natural gas distribution and storage operations must comply with a variety of statutes and regulations relating to the protection of the environment and human health and [removed: safety.][added: safety, including permitting programs implemented by federal, state, and local authorities.]

[removed: Recent and potential new executive] [added: Executive] orders issued by the [removed: current federal] [added: presidential] administration as well as local and state land use requirements can also impact our planning activities.

For discussion of environmental matters, including NOx and SO2 emission reduction requirements, regulation of CO2 emissions, wastewater discharge standards, remediation efforts, and CCR management regulations, [removed: and a discussion of litigation against Ameren Missouri with respect to NSR, the Clean Air Act, and Missouri law in connection with projects at Ameren Missouri’s Rush Island Energy Center,] see Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

The AMMO balancing authority area includes the load and most energy centers of Ameren Missouri, and had a peak demand of [removed: 7,560] [added: 7,487] MWs in [removed: 2024.][added: 2025.]

The AMIL balancing authority area includes the load of Ameren Illinois and certain Ameren Missouri energy centers located in Illinois, and had a peak demand of [removed: 8,479] [added: 8,027] MWs in [removed: 2024.][added: 2025.]

Ameren Missouri [removed: sells] [added: offers for sale] all of its capacity to the MISO and purchases the capacity it needs to supply its native load sales from the MISO.

Ameren Illinois purchases [added: all of its] capacity from the MISO and [added: hedges those purchases] through bilateral contracts resulting from IPA procurement events.

[removed: Beginning with the April 2023 auction for the June 2023 to May 2024 planning year,] [added: MISO] auctions [removed: include] [added: establish capacity for] four seasonal [added: peak] load forecasts and [removed: available capacity levels and] are designed to cover each season’s peak demand plus a target reserve margin.

Ameren Missouri [removed: expects to file] [added: filed] a notice of change in its [added: September 2023] preferred resource plan with the MoPSC in February 2025 to address new load growth opportunities resulting from entities in various industries, including data center and manufacturing, that are considering either locating or expanding their operations within Ameren Missouri’s service territory.

The 2025 Change to the 2023 PRP [removed: is expected to include,] [added: includes,] among other things, the following:

- adding 1,600 MWs of natural gas-fired simple-cycle generation by 2030, which [removed: includes] [added: will be achieved through] the [removed: 800-MW Castle Bluff Natural Gas Project] [added: natural gas generation projects] discussed in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report, and an additional 1,200 MWs by 2043;

- adding 3,200 MWs of renewable generation by 2030, which includes the [removed: 900 MWs of] solar generation projects discussed in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report, and an additional 1,500 MWs by 2035;

The need for investment in new sources of energy is dependent on several key factors, including continuation of and customer participation in energy-efficiency programs, the amount of distributed generation from customers, load growth, including demand from data centers, technological advancements, costs of generation alternatives, environmental regulation of coal-fired and natural gas-fired power plants, changes in United States energy policy and priorities under the [removed: current federal] [added: presidential] administration, and state renewable energy requirements, which could lead to the retirement of current baseload assets before the end of their current useful lives or alterations in the way those assets operate, which could result in increased capital expenditures and/or increased operations and maintenance expenses.

Steps include evaluating the potential for further diversification of Ameren Missouri’s generation portfolio through renewable energy generation, including wind and solar generation, natural gas-fired generation, including the potential to [removed: switch to hydrogen fuel and/or] blend hydrogen fuel with natural gas and install carbon capture technology, extending the operating license for the Callaway Energy Center, [added: adding new nuclear generation,] additional customer energy-efficiency and demand response programs, distributed energy resources, and energy storage.

Missouri law [removed: required Ameren Missouri to offer solar rebates through December 2023 and currently] requires [added: that] Ameren Missouri [removed: to offer] [added: offers] net metering to certain customers that install renewable generation at their premises.

In [added: 2025,] 2024, [removed: 2023,] and [removed: 2022,] [added: 2023,] Ameren Illinois procured power on behalf of its customers for [removed: 25%,] 28%, [added: 25%,] and 28%, respectively, of its total kilowatthour sales.

The IPA administers an RFP process through which Ameren Illinois procures its expected [removed: supply.]

Pursuant to [removed: the CEJA,] [added: Illinois law,] Ameren Illinois is required to file a Grid Plan with the ICC every four years.

The Grid Plan outlines how Ameren Illinois expects to invest in electric distribution infrastructure in order to support grid modernization, clean energy, energy efficiency, and the state of Illinois’ renewable energy, equity, climate, electrification, and environmental [added: goals.]

Illinois law [added: currently] requires Ameren Illinois to offer rebates and net metering to certain customers who install renewable [removed: generation or paired energy storage systems at their premises.][added: generation.]

As of December 31, [removed: 2024,] [added: 2025,] Ameren Missouri’s coal-fired energy centers represented [removed: 6%] [added: 5%] and 11% of Ameren’s and Ameren Missouri’s rate base, respectively.

The Callaway Energy Center began operation in 1984 and is [added: currently] licensed to operate until 2044.

An illustration of the Ameren Companies’ reporting structures is provided below:

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

| Natural gas delivery service | | | MoPSC | | | July 2025 | | | September 2025 | | | (c) | | | (c) | | | (c) | | | 2% | | |

| Electric energy-efficiency investments(e) | | | ICC | | | November 2025 | | | January 2026 | | | 10.65% | | | 50.00% | | | $0.5 | | | 1% | | |

In December 2025, the ICC approved a year end rate base for 2024 of $4.2 billion.

(e)Ameren Illinois electric energy-efficiency investment rates are updated annually and become effective each January.

Under current Illinois law, the ROE component of the applicable WACC is based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points and any performance-related basis-point adjustments.

Pursuant to the CRGA, beginning in 2027, the ROE component of the applicable WACC for a given year will be that year’s ICC-approved ROE for Ameren Illinois’ electric distribution service.

Under current Illinois law and the CRGA, the allowed ROE on electric energy-efficiency investments can be increased or decreased by up to 200 basis points, depending on the achievement of annual energy savings and demand goals.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

Such environmental laws regulate air emissions; protect water bodies; regulate the handling and disposal of hazardous substances and waste materials; establish siting and land use requirements; and protect against ecological impacts.

The CRGA requires the ICC and IPA to conduct a study to examine the costs and benefits of establishing a single, state-specific RTO, consolidating Illinois utilities’ RTO membership into one existing RTO, or maintaining the existing RTO membership structure.

Additional studies may be required or requested by the Illinois legislature.

The ICC and IPA must publish the study by December 2026.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

- estimated total load growth of 1.5 gigawatts by 2032 and 2.5 gigawatts by 2040;

- adding 1,000 MWs of battery storage by 2030, which includes the Big Hollow Battery Energy Storage Project discussed in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report, and an additional 800 MWs by 2042;

Additionally, in February 2026, Ameren Missouri executed electric service agreements with large load customers under the large load customer rate plan, representing 2.2 gigawatts of demand.

See Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report for more information on the large load customer rate plan.

Ameren Missouri expects to file its next preferred resource plan in September 2026.

The PPRA became effective in August 2025.

The law made modifications to integrated resource planning, which requires Missouri electric utilities to file plans for meeting their customers' long-term energy needs.

By August 2027, the MoPSC will publish a schedule for Missouri electric utilities to file integrated resource plans every four years.

The MoPSC will be required to issue an order on the plans and shall determine whether the electric utility has submitted sufficient documentation and selected preferred resource plans representing a reasonable and prudent means of serving the utility's load obligations at just and reasonable rates.

In making this determination, the MoPSC shall consider whether the plans appropriately balance specific factors described in the law.

If the MoPSC approves the plans, requests for CCNs for new generation facilities to be constructed or acquired as a part of the approved plans shall be deemed necessary and convenient and the scope of the CCN proceedings to review projects will be limited.

The approved generation facilities will also be eligible to include construction work in progress in rate base, subject to MoPSC approval, which would improve the timeliness of cash recovery.

Utilities are not allowed to capitalize allowance for funds used during construction on amounts included in rate base under this provision.

The amount of construction work in progress to be included in rate base is limited to prudently incurred expenditures made within the construction period for the facility.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

supply.

In January 2026, Ameren Illinois filed its Grid Plan for the years 2028 through 2031.

The Grid Plan will be used to align capital expenditures to operational needs and will impact rate base for future rate reviews under an MYRP or traditional rate review.

An order from the ICC is expected in December 2026.

In addition, pursuant to the CRGA, Ameren Illinois will participate in an integrated resource planning process, which is designed to align statewide electric supply and demand and establish a plan for electricity resources to reliably, affordably, and efficiently serve Illinois customers while meeting clean energy targets at the lowest cost over time.

The ICC staff, the IPA, the Illinois Finance Authority, and the Illinois Environmental Protection Agency must submit the initial integrated resource plan to the ICC no later than November 15, 2026, the second integrated resource plan to the ICC no later than September 30, 2029, and each subsequent plan to the ICC every four years thereafter no later than September 30 of the applicable year.

The cost of the customer generation rebate program is deferred as a regulatory asset, which earns a return at the applicable WACC, with the ROE based on the annual average of the monthly average yields of the 30-year United States Treasury bonds plus 580 basis points through 2026.

Pursuant to the CRGA, standalone energy storage systems will also be eligible for rebates, and the return on the deferred regulatory asset will be equal to the most recently approved ROE for Ameren Illinois electric distribution, beginning in January 2027.

The eligibility of standalone energy storage systems for rebates is subject to ICC approval, with the tariff filing due in the second half of 2026.

Ameren Illinois expects a decision on the tariff filing by the end of 2026.

| Natural gas delivery service | | | MoPSC | | | December 2021 | | | February 2022 | | | (d) | | | (d) | | | $0.3 | | | 2% | | |

(d)This rate order did not specify an ROE or a capital structure.

(e)In December 2024, the ICC issued an order in Ameren Illinois’ MYRP proceeding.

are operated under authority granted by an Act of Congress in 1905.

These environmental statutes and regulations are comprehensive and include the storage, handling, and disposal of waste materials and hazardous substances, emergency planning and response requirements, limitations and standards applicable to discharges from our facilities into the air or water that are enforced through permitting requirements, and natural resource protection laws, including those related to endangered species.

In 2022, the FERC issued an order approving changes to the annual MISO capacity auction.

Historically, the auctions were designed to cover annual peak demand plus a target reserve margin.

The seasonal auction structure was established to help to address variability in resources as the MISO begins to rely more heavily on renewable generation.

The most recent preferred resource plan was filed in September 2023.

- adding 1,000 MWs of battery storage by 2030 and an additional 800 MWs by 2042;

Ameren Missouri would be adversely affected if the MoPSC does not allow recovery of the remaining investment and decommissioning costs associated with the retirement of an energy center, as well as the ability to earn a return on that remaining investment and those decommissioning costs.

The next preferred resource plan is required to be filed by October 2026.

The difference between the cost of the solar rebates and the amount set in base rates was deferred as a regulatory asset or liability under the RESRAM, and earns carrying costs at short-term interest rates.

goals.

Ameren Illinois’ next Grid Plan is required to be filed by mid-January 2026.

The cost of the customer generation rebate program is deferred as a regulatory asset, which earns a return at the applicable WACC.

Customers that elect to receive a generation rebate and are enrolled in net metering are allowed to net their power supply service charges, but not their distribution service charges.

Customers that elect to receive energy storage rebates and have not received generation rebates are allowed to net their power supply and distribution service charges.

If 100% of the goals are achieved in 2025, 2026, and 2027, Ameren Missouri would earn performance incentive revenues of $5 million, $5 million, and $2 million, respectively.

Through 2024, Ameren Missouri has invested approximately $415 million in MEEIA 2019 customer energy-efficiency and demand response programs.

the MEEIA programs are reflected in base rates.

In June 2022, the ICC issued an order approving Ameren Illinois’ electric and natural gas energy-efficiency plans for 2022 through 2025, as well as regulatory recovery mechanisms.

The order authorized electric and natural gas energy-efficiency program expenditures of $476 million and $66 million, respectively, over the four-year period.

Ameren Illinois is required to file an updated four-year electric energy-efficiency plan with the ICC by March 2025.

Foundational to our workforce strategy are our core competencies of:

| | | | | | |

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

| •Be Strategic •Continuously Improve •Deliver Results | | | •Engage Respectfully •Foster Collaboration •Think Customer | | |

In addition to reviewing and determining the Ameren Companies’

We strive to cultivate a mission-driven, values-based culture that enables the sustainable execution of our core strategy.

We design our human capital management practices and policies to reinforce our values, shape our culture, and drive employee engagement.

We assess employee engagement through a variety of channels.

As a part of our assessment, we conduct confidential employee engagement surveys to identify areas of strength and opportunities for improvement in our employees’ experience, and take actions aimed at increasing employee engagement.

We also offer flexible work arrangements, such as permitting certain employees to work from alternate locations or to make adjustments to an employee’s daily work hours, among other things, complemented by our work to advance the digital enablement of our workforce, and have enhanced our facilities and workforce policies and practices to increase collaboration and productivity.

Talent

In order to attract and retain a skilled and highly qualified workforce, we provide opportunities for employees to expand their knowledge and skill sets, and we support their career development.

Our onboarding efforts are designed to ensure early engagement, including the opportunity to participate in mentoring programs.

Additionally, employees are encouraged to participate in technical, professional, and leadership development opportunities, and outreach initiatives to engage with the communities that we serve, among other things.

| Ameren | | | | | | 8,981 | | | | | | 13 | | | | | | 7% | | | | | |

Rewards

For additional information on material legal and administrative proceedings, see [Note 2 – Rate and Regulatory [removed: Matters](#i15112ec7ce464e3d9656f6f00b3e12db_229),] [added: Matters](#i379db4a35dfd4fdf8d9a48974b14319e_229),] [Note 9 – Callaway Energy [removed: Center](#i15112ec7ce464e3d9656f6f00b3e12db_259),] [added: Center](#i379db4a35dfd4fdf8d9a48974b14319e_262),] and [Note 14 – Commitments and [removed: Contingencies](#i15112ec7ce464e3d9656f6f00b3e12db_277)] [added: Contingencies](#i379db4a35dfd4fdf8d9a48974b14319e_280)] under Part II, Item 8, of this report.

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

| ☒ | | | Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, [removed: 2024] [added: 2025] | | |

| [removed: ] [added: ] | | | [removed: ] [added: ] | | | [removed: ] [added: ] | | |

As of June [removed: 28, 2024,] [added: 30, 2025,] the aggregate market value of Ameren Corporation’s common stock, $0.01 par value, (based upon the closing price of the common stock on the New York Stock Exchange on June [removed: 28, 2024)] [added: 30, 2025)] held by nonaffiliates was [removed: $18,953,889,643.][added: $25,948,493,142.]

All of the shares of common stock of the other registrants were held by Ameren Corporation as of June [removed: 28, 2024.][added: 30, 2025.]

The number of shares outstanding of each registrant’s classes of common stock as of January [removed: 31, 2025,] [added: 30, 2026,] were as follows:

| Ameren Corporation | | | Common stock, $0.01 par value per share | | | [removed: 269,906,252] [added: 276,424,515] | | |

Portions of the definitive proxy statement of Ameren Corporation and portions of the definitive information statements of Union Electric Company and Ameren Illinois Company for the [removed: 2025] [added: 2026] annual meetings of shareholders are incorporated by reference into Part III of this Form 10-K.

| [GLOSSARY OF TERMS AND [removed: ABBREVIATIONS](#i15112ec7ce464e3d9656f6f00b3e12db_10)] [added: ABBREVIATIONS](#i379db4a35dfd4fdf8d9a48974b14319e_10)] | | | | | | | | | [removed: [1](#i15112ec7ce464e3d9656f6f00b3e12db_10)] [added: [1](#i379db4a35dfd4fdf8d9a48974b14319e_10)] | | |

| [FORWARD-LOOKING [removed: STATEMENTS](#i15112ec7ce464e3d9656f6f00b3e12db_13)] [added: STATEMENTS](#i379db4a35dfd4fdf8d9a48974b14319e_13)] | | | | | | | | | [removed: [5](#i15112ec7ce464e3d9656f6f00b3e12db_13)] [added: [5](#i379db4a35dfd4fdf8d9a48974b14319e_13)] | | |

| Item 1. | | | [removed: [Business](#i15112ec7ce464e3d9656f6f00b3e12db_19)] [added: [Business](#i379db4a35dfd4fdf8d9a48974b14319e_19)] | | | | | | [removed: [7](#i15112ec7ce464e3d9656f6f00b3e12db_19)] [added: [7](#i379db4a35dfd4fdf8d9a48974b14319e_19)] | | |

| | | | [Business [removed: Segments](#i15112ec7ce464e3d9656f6f00b3e12db_25)] [added: Segments](#i379db4a35dfd4fdf8d9a48974b14319e_25)] | | | | | | [removed: [7](#i15112ec7ce464e3d9656f6f00b3e12db_25)] [added: [7](#i379db4a35dfd4fdf8d9a48974b14319e_25)] | | |

| | | | [Rates and [removed: Regulation](#i15112ec7ce464e3d9656f6f00b3e12db_28)] [added: Regulation](#i379db4a35dfd4fdf8d9a48974b14319e_28)] | | | | | | [removed: [8](#i15112ec7ce464e3d9656f6f00b3e12db_28)] [added: [8](#i379db4a35dfd4fdf8d9a48974b14319e_28)] | | |

| | | | [Supply of Electric [removed: Power](#i15112ec7ce464e3d9656f6f00b3e12db_34)] [added: Power](#i379db4a35dfd4fdf8d9a48974b14319e_34)] | | | | | | [removed: [10](#i15112ec7ce464e3d9656f6f00b3e12db_34)] [added: [10](#i379db4a35dfd4fdf8d9a48974b14319e_34)] | | |

| | | | [Power [removed: Generation](#i15112ec7ce464e3d9656f6f00b3e12db_37)] [added: Generation](#i379db4a35dfd4fdf8d9a48974b14319e_37)] | | | | | | [removed: [12](#i15112ec7ce464e3d9656f6f00b3e12db_37)] [added: [12](#i379db4a35dfd4fdf8d9a48974b14319e_37)] | | |

| | | | [Renewable Energy and Zero Emission [removed: Standards](#i15112ec7ce464e3d9656f6f00b3e12db_40)] [added: Standards](#i379db4a35dfd4fdf8d9a48974b14319e_40)] | | | | | | [removed: [12](#i15112ec7ce464e3d9656f6f00b3e12db_40)] [added: [13](#i379db4a35dfd4fdf8d9a48974b14319e_40)] | | |

| | | | [Customer Energy-Efficiency [removed: Programs](#i15112ec7ce464e3d9656f6f00b3e12db_43)] [added: Programs](#i379db4a35dfd4fdf8d9a48974b14319e_43)] | | | | | | [removed: [13](#i15112ec7ce464e3d9656f6f00b3e12db_43)] [added: [14](#i379db4a35dfd4fdf8d9a48974b14319e_43)] | | |

| | | | [Natural Gas Supply for [removed: Distribution](#i15112ec7ce464e3d9656f6f00b3e12db_46)] [added: Distribution](#i379db4a35dfd4fdf8d9a48974b14319e_46)] | | | | | | [removed: [14](#i15112ec7ce464e3d9656f6f00b3e12db_46)] [added: [15](#i379db4a35dfd4fdf8d9a48974b14319e_46)] | | |

| | | | [Human Capital [removed: Management](#i15112ec7ce464e3d9656f6f00b3e12db_49)] [added: Management](#i379db4a35dfd4fdf8d9a48974b14319e_49)] | | | | | | [removed: [14](#i15112ec7ce464e3d9656f6f00b3e12db_49)] [added: [15](#i379db4a35dfd4fdf8d9a48974b14319e_49)] | | |

| | | | [Industry [removed: Issues](#i15112ec7ce464e3d9656f6f00b3e12db_55)] [added: Issues](#i379db4a35dfd4fdf8d9a48974b14319e_55)] | | | | | | [removed: [16](#i15112ec7ce464e3d9656f6f00b3e12db_55)] [added: [17](#i379db4a35dfd4fdf8d9a48974b14319e_55)] | | |

| | | | [Operating [removed: Statistics](#i15112ec7ce464e3d9656f6f00b3e12db_58)] [added: Statistics](#i379db4a35dfd4fdf8d9a48974b14319e_58)] | | | | | | [removed: [18](#i15112ec7ce464e3d9656f6f00b3e12db_58)] [added: [19](#i379db4a35dfd4fdf8d9a48974b14319e_58)] | | |

| | | | [Available [removed: Information](#i15112ec7ce464e3d9656f6f00b3e12db_61)] [added: Information](#i379db4a35dfd4fdf8d9a48974b14319e_61)] | | | | | | [removed: [20](#i15112ec7ce464e3d9656f6f00b3e12db_61)] [added: [21](#i379db4a35dfd4fdf8d9a48974b14319e_61)] | | |

| Item 1A. | | | [Risk [removed: Factors](#i15112ec7ce464e3d9656f6f00b3e12db_64)] [added: Factors](#i379db4a35dfd4fdf8d9a48974b14319e_64)] | | | | | | [removed: [20](#i15112ec7ce464e3d9656f6f00b3e12db_64)] [added: [21](#i379db4a35dfd4fdf8d9a48974b14319e_64)] | | |

| Item 1B. | | | [Unresolved Staff [removed: Comments](#i15112ec7ce464e3d9656f6f00b3e12db_67)] [added: Comments](#i379db4a35dfd4fdf8d9a48974b14319e_67)] | | | | | | [removed: [30](#i15112ec7ce464e3d9656f6f00b3e12db_67)] [added: [31](#i379db4a35dfd4fdf8d9a48974b14319e_67)] | | |

| Item 1C. | | | [removed: [Cybersecurity](#i15112ec7ce464e3d9656f6f00b3e12db_70)] [added: [Cybersecurity](#i379db4a35dfd4fdf8d9a48974b14319e_70)] | | | | | | [removed: [30](#i15112ec7ce464e3d9656f6f00b3e12db_70)] [added: [31](#i379db4a35dfd4fdf8d9a48974b14319e_70)] | | |

| Item 2. | | | [removed: [Properties](#i15112ec7ce464e3d9656f6f00b3e12db_73)] [added: [Properties](#i379db4a35dfd4fdf8d9a48974b14319e_73)] | | | | | | [removed: [31](#i15112ec7ce464e3d9656f6f00b3e12db_73)] [added: [32](#i379db4a35dfd4fdf8d9a48974b14319e_73)] | | |

| Item 3. | | | [Legal [removed: Proceedings](#i15112ec7ce464e3d9656f6f00b3e12db_76)] [added: Proceedings](#i379db4a35dfd4fdf8d9a48974b14319e_76)] | | | | | | [removed: [33](#i15112ec7ce464e3d9656f6f00b3e12db_76)] [added: [34](#i379db4a35dfd4fdf8d9a48974b14319e_76)] | | |

| Item 4. | | | [Mine Safety [removed: Disclosures](#i15112ec7ce464e3d9656f6f00b3e12db_79)] [added: Disclosures](#i379db4a35dfd4fdf8d9a48974b14319e_79)] | | | | | | [removed: [33](#i15112ec7ce464e3d9656f6f00b3e12db_79)] [added: [34](#i379db4a35dfd4fdf8d9a48974b14319e_79)] | | |

| Item 5. | | | [Market for Registrants’ Common Equity, Related Stockholder [removed: Matters](#i15112ec7ce464e3d9656f6f00b3e12db_88) [and] [added: Matters and] Issuer Purchases of Equity [removed: Securities](#i15112ec7ce464e3d9656f6f00b3e12db_88)] [added: Securities](#i379db4a35dfd4fdf8d9a48974b14319e_88)] | | | | | | [removed: [34](#i15112ec7ce464e3d9656f6f00b3e12db_88)] [added: [37](#i379db4a35dfd4fdf8d9a48974b14319e_88)] | | |

| Item 6. | | | [removed: [(Reserved)](#i15112ec7ce464e3d9656f6f00b3e12db_91)] [added: [(Reserved)](#i379db4a35dfd4fdf8d9a48974b14319e_91)] | | | | | | [removed: [35](#i15112ec7ce464e3d9656f6f00b3e12db_91)] [added: [38](#i379db4a35dfd4fdf8d9a48974b14319e_91)] | | |

| Item 7. | | | [Management’s Discussion and Analysis of Financial Condition and Results of [removed: Operations](#i15112ec7ce464e3d9656f6f00b3e12db_97)] [added: Operations](#i379db4a35dfd4fdf8d9a48974b14319e_97)] | | | | | | [removed: [35](#i15112ec7ce464e3d9656f6f00b3e12db_97)] [added: [38](#i379db4a35dfd4fdf8d9a48974b14319e_97)] | | |

| | | | [removed: [Overview](#i15112ec7ce464e3d9656f6f00b3e12db_103)] [added: [Overview](#i379db4a35dfd4fdf8d9a48974b14319e_103)] | | | | | | [removed: [36](#i15112ec7ce464e3d9656f6f00b3e12db_103)] [added: [39](#i379db4a35dfd4fdf8d9a48974b14319e_103)] | | |

| | | | [Results of [removed: Operations](#i15112ec7ce464e3d9656f6f00b3e12db_109)] [added: Operations](#i379db4a35dfd4fdf8d9a48974b14319e_109)] | | | | | | [removed: [41](#i15112ec7ce464e3d9656f6f00b3e12db_109)] [added: [42](#i379db4a35dfd4fdf8d9a48974b14319e_109)] | | |

| | | | [Liquidity and Capital [removed: Resources](#i15112ec7ce464e3d9656f6f00b3e12db_124)] [added: Resources](#i379db4a35dfd4fdf8d9a48974b14319e_124)] | | | | | | [removed: [57](#i15112ec7ce464e3d9656f6f00b3e12db_124)] [added: [57](#i379db4a35dfd4fdf8d9a48974b14319e_124)] | | |

| | | | [removed: [Outlook](#i15112ec7ce464e3d9656f6f00b3e12db_157)] [added: [Outlook](#i379db4a35dfd4fdf8d9a48974b14319e_157)] | | | | | | [removed: [67](#i15112ec7ce464e3d9656f6f00b3e12db_157)] [added: [67](#i379db4a35dfd4fdf8d9a48974b14319e_157)] | | |

| | | | [Regulatory [removed: Matters](#i15112ec7ce464e3d9656f6f00b3e12db_160)] [added: Matters](#i379db4a35dfd4fdf8d9a48974b14319e_160)] | | | | | | [removed: [73](#i15112ec7ce464e3d9656f6f00b3e12db_160)] [added: [73](#i379db4a35dfd4fdf8d9a48974b14319e_160)] | | |

| | | | [Accounting [removed: Matters](#i15112ec7ce464e3d9656f6f00b3e12db_163)] [added: Matters](#i379db4a35dfd4fdf8d9a48974b14319e_163)] | | | | | | [removed: [73](#i15112ec7ce464e3d9656f6f00b3e12db_163)] [added: [73](#i379db4a35dfd4fdf8d9a48974b14319e_163)] | | |

| Item 7A. | | | [Quantitative and Qualitative Disclosures About Market [removed: Risk](#i15112ec7ce464e3d9656f6f00b3e12db_169)] [added: Risk](#i379db4a35dfd4fdf8d9a48974b14319e_169)] | | | | | | [removed: [77](#i15112ec7ce464e3d9656f6f00b3e12db_169)] [added: [77](#i379db4a35dfd4fdf8d9a48974b14319e_169)] | | |

| Item 8. | | | [Financial Statements and Supplementary [removed: Data](#i15112ec7ce464e3d9656f6f00b3e12db_175)] [added: Data](#i379db4a35dfd4fdf8d9a48974b14319e_175)] | | | | | | [removed: [80](#i15112ec7ce464e3d9656f6f00b3e12db_175)] [added: [80](#i379db4a35dfd4fdf8d9a48974b14319e_175)] | | |

| | | | [Ameren [removed: Corporation](#i15112ec7ce464e3d9656f6f00b3e12db_187)] [added: Corporation](#i379db4a35dfd4fdf8d9a48974b14319e_187)] | | | | | | [removed: [86](#i15112ec7ce464e3d9656f6f00b3e12db_187)] [added: [86](#i379db4a35dfd4fdf8d9a48974b14319e_187)] | | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

| [PART I](#i379db4a35dfd4fdf8d9a48974b14319e_16) | | | | | | | | | | | |

| | | | [General](#i379db4a35dfd4fdf8d9a48974b14319e_22) | | | | | | [7](#i379db4a35dfd4fdf8d9a48974b14319e_22) | | |

| | | | [Transmission](#i379db4a35dfd4fdf8d9a48974b14319e_31) | | | | | | [10](#i379db4a35dfd4fdf8d9a48974b14319e_31) | | |

| [Information about Our Executive Officers](#i379db4a35dfd4fdf8d9a48974b14319e_82) | | | | | | | | | [35](#i379db4a35dfd4fdf8d9a48974b14319e_82) | | |

| [PART II](#i379db4a35dfd4fdf8d9a48974b14319e_85) | | | | | | | | | | | |

| [PART III](#i379db4a35dfd4fdf8d9a48974b14319e_316) | | | | | | | | | | | |

| [PART IV](#i379db4a35dfd4fdf8d9a48974b14319e_334) | | | | | | | | | | | |

| | | | [EXHIBIT INDEX](#i379db4a35dfd4fdf8d9a48974b14319e_355) | | | | | | [172](#i379db4a35dfd4fdf8d9a48974b14319e_355) | | |

| [SIGNATURES](#i379db4a35dfd4fdf8d9a48974b14319e_361) | | | | | | | | | [180](#i379db4a35dfd4fdf8d9a48974b14319e_361) | | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

CRGA – Clean and Reliable Grid Affordability Act, an Illinois law that modifies the ROE component of the applicable WACC that Ameren Illinois will use to calculate its return on energy-efficiency investments beginning in 2027, increases the annual spending cap on energy-efficiency investments beginning in 2027, establishes an integrated resource planning process, establishes an energy storage credit

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

procurement program, and requires the ICC and IPA to conduct a study to examine the costs and benefits related to an RTO, among other things.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

OBBBA – The One Big Beautiful Bill Act, federal legislation enacted in July 2025.

PPRA – Power Predictability and Reliability Act, a Missouri law effective August 2025 that modifies the PISA and integrated resource planning process, requires electric utilities to submit service tariff schedules for high-demand customers, allows the MoPSC to authorize the inclusion of construction work in progress in rate base for new natural gas-fired generation facilities and new generation facilities approved through integrated resource planning, and allows natural gas utilities to file regulatory rate reviews using a future test year, among other things.

The QIP expired in December 2023 and remains subject to reconciliation proceedings.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

- our ability to realize and support forecasted energy demand and capacity from new and potential new customers, including demand growth dependent on the addition of new data centers and other large primary service customers within our service territories, such as the large load customers that signed electric service agreements with Ameren Missouri in February 2026;

- the presidential administration’s change in federal domestic energy policy to support investment in fossil fuel infrastructure and the effect it has on Ameren Missouri’s ability to construct and/or acquire renewable energy generation facilities and battery storage;

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

failure to implement our investment plans or to protect sensitive customer information, increases in rates, negative media coverage, or concerns about company policies or practices;

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

| [PART I](#i15112ec7ce464e3d9656f6f00b3e12db_16) | | | | | | | | | | | |

| | | | [General](#i15112ec7ce464e3d9656f6f00b3e12db_22) | | | | | | [7](#i15112ec7ce464e3d9656f6f00b3e12db_22) | | |

| | | | [Transmission](#i15112ec7ce464e3d9656f6f00b3e12db_31) | | | | | | [10](#i15112ec7ce464e3d9656f6f00b3e12db_31) | | |

| [PART II](#i15112ec7ce464e3d9656f6f00b3e12db_85) | | | | | | | | | | | |

| [PART III](#i15112ec7ce464e3d9656f6f00b3e12db_307) | | | | | | | | | | | |

| [PART IV](#i15112ec7ce464e3d9656f6f00b3e12db_325) | | | | | | | | | | | |

| | | | [EXHIBIT INDEX](#i15112ec7ce464e3d9656f6f00b3e12db_349) | | | | | | [171](#i15112ec7ce464e3d9656f6f00b3e12db_349) | | |

| [SIGNATURES](#i15112ec7ce464e3d9656f6f00b3e12db_352) | | | | | | | | | [179](#i15112ec7ce464e3d9656f6f00b3e12db_352) | | |

CDP – A not-for-profit entity that administers a global disclosure system related to environmental matters, among other things.

Deferred payment arrangement – A payment option that allows certain Ameren Missouri and Ameren Illinois retail customers to pay a utility bill balance over an extended period of time, generally up to 12 months.

FEJA – Future Energy Jobs Act, an Illinois law that allows Ameren Illinois to earn a return on its electric energy-efficiency investments, decouples electric distribution revenues from sales volumes, offers customer rebates for installing distributed generation, and includes extensions and modifications of certain IEIMA performance-based framework provisions, among other things.

The decoupling provisions ensure that electric distribution revenues are not affected by changes in sales volumes, including those resulting from deviations from normal weather conditions.

MoOPC – Missouri Office of Public Counsel.

The QIP expired in December 2023.

energy storage, and private generation sources, which generate electricity at the site of consumption and are becoming increasingly cost-competitive;

- Ameren Illinois’ ability to achieve the performance standards applicable to its electric distribution business and electric customer energy-efficiency goals and the resulting impact on its allowed ROE;

- the inability of our counterparties to perform their obligations, disruptions in the capital and credit markets, prolonged government shutdowns or defunding, acts of sabotage or terrorism, including cyberattacks and physical attacks, and other impacts on business, economic, and geopolitical conditions, including inflation, tariffs, trade wars, or recession.

The committee has primary responsibility for oversight of cybersecurity and digital technology risk management, including the programs, policies, procedures, processes, controls and safeguards for digital technology, information security, prevention and detection of cybersecurity incidents or data breaches, [added: legislative] and [added: regulatory compliance, and] cybersecurity and digital technology matters as they relate to crisis preparedness, incident response plans, and disaster recovery and business continuity capabilities.

The committee receives regular updates from the Chief Information Security Officer, the Chief [added: Digital and] Information Officer, executive management, and other members of senior management who collectively maintain the responsibility for both the execution and ongoing management of Ameren’s cybersecurity program and respective initiatives.

In addition, Ameren’s board of directors [removed: participate] [added: participates] in [added: threat briefings and] periodic [removed: cybersecurity] drills to prepare for potential crisis scenarios.

To manage against existing and emerging cybersecurity threats, we maintain enterprise-wide cybersecurity, crisis management, and information security policies and regular [added: awareness] training and tests that reinforce the acceptable use of Ameren's information assets, protection of customer and employee data, and the role each employee plays in protecting Ameren against cybersecurity threats.

Ameren [removed: employs] [added: applies] a third-party cybersecurity risk management program, which extends the governance elements of Ameren’s cybersecurity program, in addition to other diligence measures, to our critical third-party providers and suppliers.

The supply chain and third-party risks introduced to Ameren are evaluated prior to the commencement of any new engagement or relationship, monitored closely throughout the lifecycle of the supplier [added: relationship] and managed through [added: data] privacy and cybersecurity provisions within the respective commercial contracts.

[removed: Our program effectiveness is] measured through formal cybersecurity scorecards and metrics reported to senior-level Ameren officers, the risk management steering [added: committee, and the Cybersecurity and Digital Technology Committee.]

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

Ameren's cybersecurity program and team are led by the Chief Information Security Officer, who has nearly two decades of experience in cybersecurity, information technology, risk management, and business operations across the power and utilities sector and other industries.

The Chief Information Security Officer provides strategic leadership and vision to strengthen Ameren’s security posture and promote resilience in an evolving threat landscape.

Our program effectiveness is

Ameren's cybersecurity program and team are led by the Chief Information Security Officer, who possesses over 25 years of critical infrastructure experience both managing and protecting information systems in concert with extensive cybersecurity operations and leadership roles.

committee, and the Cybersecurity and Digital Technology Committee.

See also Note [removed: 5 – Long-term Debt and Equity Financings and Note] 14 – Commitments and Contingencies under Part II, Item 8, of this report.

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

The following table shows the anticipated capability of our energy centers at the time of the expected [removed: 2025] [added: 2026] peak summer electrical demand for all energy centers owned as of December 31, [removed: 2024:][added: 2025, except as otherwise noted below:]

| Primary Fuel Source | | | Energy Center | | | Location | | | Net [removed: Kilowatt] [added: Megawatt] Capability(a) | | |

| Coal | | | Labadie(b) | | | Franklin County, Missouri | | | [removed: 2,372,000] [added: 2,372] | | |

| | | | Sioux(c) | | | St. Charles County, Missouri | | | [removed: 972,000] [added: 972] | | |

| Total coal | | | | | | | | | [removed: 3,344,000] [added: 3,344] | | |

| Nuclear | | | Callaway(d) | | | Callaway County, Missouri | | | [removed: 1,194,000] [added: 1,194] | | |

| Hydroelectric | | | Osage(d) | | | Lakeside, Missouri | | | [removed: 235,000] [added: 235] | | |

| | | | Keokuk | | | Keokuk, Iowa | | | [removed: 148,000] [added: 148] | | |

| Total hydroelectric | | | | | | | | | [removed: 383,000] [added: 383] | | |

| Pumped-storage | | | Taum Sauk(d) | | | Reynolds County, Missouri | | | [removed: 440,000] [added: 440] | | |

| Wind | | | High Prairie | | | Adair and Schuyler Counties, Missouri | | | [removed: 400,000] [added: 400] | | |

| | | | Atchison | | | Atchison County, Missouri | | | [removed: 298,800] [added: 299] | | |

| Total wind | | | | | | | | | [removed: 698,800] [added: 699] | | |

| [removed: Solar] | | | Huck [removed: Finn(e)] [added: Finn(f)] | | | Audrain and Ralls Counties, Missouri | | | [removed: 200,000] [added: 200] | | |

| | | | Boomtown | | | White County, Illinois | | | [removed: 150,000] [added: 153] | | |

| | | | Cass County | | | Cass County, Illinois | | | [removed: 150,000] [added: 150] | | |

| | | | Other [removed: Solar(f)] [added: Solar(g)] | | | Various | | | [removed: 15,300] [added: 15] | | |

| Total solar | | | | | | | | | [removed: 515,300] [added: 918] | | |

| Natural gas (CTs) | | | Audrain | | | Audrain County, Missouri | | | [removed: 608,000] [added: 608] | | |

| | | | [removed: Venice(g)] [added: Venice(h)] | | | Venice, Illinois | | | [removed: 487,000] [added: 486] | | |

| | | | Goose [removed: Creek(g)] [added: Creek(h)] | | | Piatt County, Illinois | | | [removed: 438,000] [added: 438] | | |

| | | | [removed: Pinckneyville(g)] [added: Pinckneyville(h)] | | | Pinckneyville, Illinois | | | [removed: 316,000] [added: 316] | | |

| | | | Raccoon [removed: Creek(g)] [added: Creek(h)] | | | Clay County, Illinois | | | [removed: 304,000] [added: 304] | | |

| | | | [removed: Kinmundy(g)] [added: Kinmundy(h)] | | | Kinmundy, Illinois | | | [removed: 210,000] [added: 210] | | |

| | | | Peno Creek | | | Bowling Green, Missouri | | | [removed: 172,000] [added: 172] | | |

| Total natural gas | | | | | | | | | [removed: 2,535,000] [added: 2,534] | | |

| Oil (CTs) | | | [removed: Fairgrounds(h)] [added: Fairgrounds(i)] | | | Jefferson City, Missouri | | | [removed: 55,000] [added: 55] | | |

| | | | [removed: Mexico(h)] [added: Mexico(i)] | | | Mexico, Missouri | | | [removed: 54,000] [added: 54] | | |

| | | | [removed: Moberly(h)] [added: Moberly(i)] | | | Moberly, Missouri | | | [removed: 54,000] [added: 54] | | |

| | | | [removed: Moreau(h)] [added: Moreau(i)] | | | Jefferson City, Missouri | | | [removed: 54,000] [added: 54] | | |

| Total oil | | | | | | | | | [removed: 217,000] [added: 217] | | |

| Methane gas (CT) | | | Maryland Heights | | | Maryland Heights, Missouri | | | [removed: 9,000] [added: 9] | | |

| Total Ameren Missouri | | | | | | | | | [removed: 9,336,100] [added: 9,738] | | |

| Solar | | | East St. Louis I | | | East St. Louis, Illinois | | | [removed: 2,500] [added: 2] | | |

| | | | East St. Louis II | | | East St. Louis, Illinois | | | [removed: 1,900] [added: 2] | | |

| Total Ameren | | | | | | | | | [removed: 9,340,500] [added: 9,742] | | |

(a)Net [removed: kilowatt] [added: megawatt] capability, except for wind and solar generating facilities, is the generating capacity available for dispatch from the energy center into the electric transmission grid.

(b)The Labadie Energy Center is scheduled to retire [removed: 1,186,000 kilowatts] [added: 1,186 megawatts] by 2036 and [removed: 1,186,000 kilowatts] [added: 1,186 megawatts] by 2042.

| Solar | | | Split Rail(e) | | | Warren County, Missouri | | | 300 | | |

| | | | Vandalia(f) | | | Audrain County, Missouri | | | 50 | | |

| | | | Bowling Green(e) | | | Pike County, Missouri | | | 50 | | |

(c)The Sioux Energy Center is scheduled to retire by 2032.

(e)In February 2026, Ameren Missouri acquired the Split Rail Solar Project.

The Bowling Green and Split Rail solar projects are expected to be placed in-service in the first quarter of 2026 and in the second quarter of 2026, respectively, before 2026 peak summer electrical demand.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

(c)Ameren Missouri plans to extend the retirement date of the Sioux Energy Center from 2030 to 2032, which is subject to the approval of a change in depreciable lives of the energy center’s assets by the MoPSC in Ameren Missouri’s 2024 electric service regulatory rate review.

See Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report for additional information on Ameren Missouri’s request to extend the retirement date of the Sioux Energy Center.

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

INFORMATION ABOUT OUR EXECUTIVE OFFICERS:

The executive officers of the Ameren Companies, including major subsidiaries, are listed below, along with their ages as of December 31, 2025, all their positions and offices held with the Ameren Companies as of February 18, 2026, their tenures as officers, and their titles for at least the last five years.

AMEREN CORPORATION:

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

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

| Name | | | Age | | | Positions | | | Period | | |

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

| Martin J. Lyons, Jr. | | | 59 | | | Chairman, President, and Chief Executive Officer; Ameren | | | January 2022(a) – Present | | |

| | | | | | | Chairman and President; Ameren Missouri | | | December 2019 – January 2022 | | |

| Michael L. Moehn | | | 56 | | | Group President, Ameren Utilities; Ameren | | | January 2026 – Present | | |

| | | | | | | Interim Chairman and President; Ameren Missouri | | | October 2025 – Present | | |

| | | | | | | Senior Executive Vice President and Chief Financial Officer; Ameren | | | March 2023 – December 2025 | | |

| | | | | | | Chairman and President; Ameren Services | | | December 2019 – December 2025 | | |

| | | | | | | Executive Vice President and Chief Financial Officer; Ameren | | | December 2019 – February 2023 | | |

| Leonard P. Singh | | | 56 | | | Executive Vice President and Chief Financial Officer; Ameren | | | January 2026 – Present | | |

| | | | | | | Chairman and President; Ameren Services | | | January 2026 – Present | | |

| | | | | | | Chairman and President; Ameren Illinois | | | August 2022(b) – December 2025 | | |

| David M. Feinberg | | | 56 | | | Executive Vice President, General Counsel, and Secretary; Ameren | | | November 2025(c) – Present | | |

| Theresa A. Shaw | | | 53 | | | Senior Vice President, Chief Accounting and Transformation Officer; Ameren | | | January 2026 – Present | | |

| | | | | | | Senior Vice President, Finance, and Chief Accounting Officer; Ameren | | | August 2021 – December 2025 | | |

| | | | | | | Senior Vice President, Regulatory Affairs and Financial Services; Ameren Illinois | | | September 2019 – August 2021 | | |

(a)Elected President and Chief Executive Officer of Ameren in January 2022, and Chairman of Ameren in November 2023.

(b)Leonard P.

Singh served as Senior Vice President of Consolidated Edison Company of New York from December 2020 to June 2022.

(c)David M.

Feinberg served as Executive Vice President, General Counsel, and Secretary of American Electric Power Company, Inc. from January 2013 to August 2025.

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

SUBSIDIARIES:

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

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

| Name | | | Age | | | Positions | | | Period | | |

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

| Ajay K. Arora | | | 55 | | | Senior Vice President and Chief Development Officer; Ameren Missouri | | | January 2025 – Present | | |

| | | | | | | Senior Vice President and Chief Renewable Development Officer; Ameren Missouri | | | September 2022 – December 2024 | | |

| | | | | | | Vice President and Chief Renewable Development Officer; Ameren Missouri | | | December 2020 – September 2022 | | |

| Mark C. Lindgren | | | 58 | | | Executive Vice President, Communications, and Chief Human Resources Officer; Ameren Services | | | March 2023 – Present | | |

| | | | | | | Senior Vice President, Corporate Communications, and Chief Human Resources Officer; Ameren Services | | | September 2015 – February 2023 | | |

| Ryan J. Martin | | | 52 | | | Senior Vice President, Finance; Ameren Services | | | January 2026 – Present | | |

| | | | | | | Senior Vice President, Corporate Strategy, Risk and Investor Relations; Ameren Services | | | May 2025 – December 2025 | | |

| | | | | | | Vice President, Corporate Strategy, Risk and Investor Relations; Ameren Services | | | November 2023 – May 2025 | | |

Ameren common shareholders of record totaled [removed: 33,414] [added: 31,149] on January [removed: 31, 2025.][added: 30, 2026.]

Ameren Corporation, Ameren Missouri, and Ameren Illinois did not purchase any equity securities reportable under Item 703 of Regulation S-K during the period from October 1, [removed: 2024,] [added: 2025,] to December 31, [removed: 2024.][added: 2025.]

The following graph shows Ameren’s cumulative TSR during the five years ended December 31, [removed: 2024.][added: 2025.]

The comparison assumes that $100 was invested on December 31, [removed: 2019,] [added: 2020,] in Ameren common stock and in each of the indices shown and that all of the dividends were reinvested.

[removed: ][added: ]

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

| December 31, | | | [removed: 2019] [added: 2020] | | | | | | [removed: 2020] [added: 2021] | | | | | | [removed: 2021] [added: 2022] | | | | | | [removed: 2022] [added: 2023] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2024] [added: 2025] | | |

| Ameren (AEE) | | | $ | 100.00 | | | | | $ | 117.09 | | | | | $ | 120.06 | | | | | $ | 100.76 | | | | | $ | 128.48 | | | | | $ | 148.15 | |

| S&P 500 Index | | | 100.00 | | | | | | 128.68 | | | | | | 105.36 | | | | | | 133.03 | | | | | | 166.28 | | | | | | 195.98 | | |

| S&P 500 Utility Index | | | 100.00 | | | | | | 117.67 | | | | | | 119.51 | | | | | | 111.05 | | | | | | 137.07 | | | | | | 159.06 | | |

| Philadelphia Utility Index | | | 100.00 | | | | | | 118.24 | | | | | | 119.01 | | | | | | 108.10 | | | | | | 130.68 | | | | | | 153.04 | | |

| Ameren (AEE) | | | $ | 100.00 | | | | | $ | 104.27 | | | | | $ | 122.09 | | | | | $ | 125.19 | | | | | $ | 105.07 | | | | | $ | 133.96 | |

| S&P 500 Index | | | 100.00 | | | | | | 118.39 | | | | | | 152.34 | | | | | | 124.73 | | | | | | 157.48 | | | | | | 196.85 | | |

| S&P 500 Utility Index | | | 100.00 | | | | | | 100.52 | | | | | | 118.29 | | | | | | 120.14 | | | | | | 111.63 | | | | | | 137.79 | | |

| Philadelphia Utility Index | | | 100.00 | | | | | | 102.72 | | | | | | 121.46 | | | | | | 122.25 | | | | | | 111.05 | | | | | | 134.24 | | |

We have audited the accompanying consolidated balance sheet of Ameren Corporation and its subsidiaries (the “Company”) as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] and the related consolidated statement of income and comprehensive income, of shareholders’ equity and of cash flows for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] including the related notes and financial statement schedules listed in the index appearing under Item 15(a)(2) (collectively referred to as the “consolidated financial statements”).

We also have audited 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 (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, [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.

Also 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 the COSO.

[removed: [Table](#i15112ec7ce464e3d9656f6f00b3e12db_7)] [added: [Table](#i379db4a35dfd4fdf8d9a48974b14319e_7)] [of [removed: Contents](#i15112ec7ce464e3d9656f6f00b3e12db_7)][added: Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)]

As of December 31, [removed: 2024,] [added: 2025,] there were approximately [removed: $2.8] [added: $2.9] billion of regulatory assets and approximately [removed: $6.0] [added: $6.4] billion of regulatory liabilities.

We have audited the accompanying consolidated balance sheet of Union Electric Company and its subsidiaries (the “Company”) as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] and the related consolidated statement of income, of shareholders’ equity and of cash flows for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] including the related notes and financial statement schedule listed in the index appearing under Item 15(a)(2) (collectively referred to as the “consolidated financial statements”).

In our opinion, the consolidated 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.

As of December 31, [removed: 2024,] [added: 2025,] there were approximately [removed: $1.4] [added: $1.6] billion of regulatory assets and approximately [removed: $3.2] [added: $3.3] billion of regulatory liabilities.

We have audited the accompanying balance sheet of Ameren Illinois Company (the “Company”) as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] and the related statement of income, of shareholders’ equity and of cash flows for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] including the related notes and financial statement schedule listed in the index appearing under Item 15(a)(2) (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.

As of December 31, [removed: 2024,] [added: 2025,] there were approximately [removed: $1.3] [added: $1.2] billion of regulatory assets and approximately [removed: $2.7] [added: $2.9] billion of regulatory liabilities.

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

| Electric | | | $ | [removed: 6,540] [added: 7,668] | | | | | $ | [removed: 6,439] [added: 6,540] | | | | | $ | [removed: 6,581] [added: 6,439] | |

| Natural gas | | | [removed: 1,083] [added: 1,131] | | | | | | [removed: 1,061] [added: 1,083] | | | | | | [removed: 1,376] [added: 1,061] | | |

| Total operating revenues | | | [removed: 7,623] [added: 8,799] | | | | | | [removed: 7,500] [added: 7,623] | | | | | | [removed: 7,957] [added: 7,500] | | |

| Fuel and purchased power | | | [removed: 1,681] [added: 2,306] | | | | | | [removed: 1,812] [added: 1,681] | | | | | | [removed: 2,020] [added: 1,812] | | |

| Natural gas purchased for resale | | | [removed: 320] [added: 348] | | | | | | [removed: 355] [added: 320] | | | | | | [removed: 657] [added: 355] | | |

| Other operations and maintenance | | | [removed: 1,969] [added: 1,974] | | | | | | [removed: 1,866] [added: 1,969] | | | | | | [removed: 1,937] [added: 1,866] | | |

| Depreciation and amortization | | | [removed: 1,590] [added: 1,568] | | | | | | [removed: 1,387] [added: 1,590] | | | | | | [removed: 1,289] [added: 1,387] | | |

| Taxes other than income taxes | | | [removed: 547] [added: 577] | | | | | | [removed: 522] [added: 547] | | | | | | [removed: 539] [added: 522] | | |

| Total operating expenses | | | [removed: 6,107] [added: 6,773] | | | | | | [removed: 5,942] [added: 6,107] | | | | | | [removed: 6,442] [added: 5,942] | | |

| Operating Income | | | [removed: 1,516] [added: 2,026] | | | | | | [removed: 1,558] [added: 1,516] | | | | | | [removed: 1,515] [added: 1,558] | | |

| Other Income, Net | | | [removed: 417] [added: 347] | | | | | | [removed: 348] [added: 417] | | | | | | [removed: 226] [added: 348] | | |

| Interest Charges | | | [removed: 663] [added: 776] | | | | | | [removed: 566] [added: 663] | | | | | | [removed: 486] [added: 566] | | |

| Income Before Income Taxes | | | [removed: 1,270] [added: 1,597] | | | | | | [removed: 1,340] [added: 1,270] | | | | | | [removed: 1,255] [added: 1,340] | | |

| Income Taxes | | | [removed: 83] [added: 136] | | | | | | [removed: 183] [added: 83] | | | | | | [removed: 176] [added: 183] | | |

| Net Income | | | [removed: 1,187] [added: 1,461] | | | | | | [removed: 1,157] [added: 1,187] | | | | | | [removed: 1,079] [added: 1,157] | | |

| Net Income Attributable to Ameren Common Shareholders | | | $ | [removed: 1,182] [added: 1,456] | | | | | $ | [removed: 1,152] [added: 1,182] | | | | | $ | [removed: 1,074] [added: 1,152] | |

| Net Income | | | $ | [removed: 1,187] [added: 1,461] | | | | | $ | [removed: 1,157] [added: 1,187] | | | | | $ | [removed: 1,079] [added: 1,157] | |

| Pension and other postretirement benefit plan activity, net of income taxes (benefit) of [added: $1,] $—, [removed: $(2),] and [removed: $(4),] [added: $(2),] respectively | | | [removed: (3)] [added: 3] | | | | | | [removed: (5)] [added: (3)] | | | | | | [removed: (14)] [added: (5)] | | |

| Unrealized net gain on derivative hedging instruments, net of income taxes of [removed: $—,] [added: $2,] $—, and $—, respectively | | | 3 | | | | | | [removed: —] [added: 3] | | | | | | — | | |

| Comprehensive Income | | | [removed: 1,187] [added: 1,467] | | | | | | [removed: 1,152] [added: 1,187] | | | | | | [removed: 1,065] [added: 1,152] | | |

| Comprehensive Income Attributable to Ameren Common Shareholders | | | $ | [removed: 1,182] [added: 1,462] | | | | | $ | [removed: 1,147] [added: 1,182] | | | | | $ | [removed: 1,060] [added: 1,147] | |

| Earnings per Common Share – Basic | | | $ | [removed: 4.43] [added: 5.38] | | | | | $ | [removed: 4.39] [added: 4.43] | | | | | $ | [removed: 4.16] [added: 4.39] | |

| Earnings per Common Share – Diluted | | | $ | [removed: 4.42] [added: 5.35] | | | | | $ | [removed: 4.38] [added: 4.42] | | | | | $ | [removed: 4.14] [added: 4.38] | |

| Weighted-average Common Shares Outstanding – Basic | | | [removed: 266.8] [added: 270.5] | | | | | | [removed: 262.8] [added: 266.8] | | | | | | [removed: 258.4] [added: 262.8] | | |

| Weighted-average Common Shares Outstanding – Diluted | | | [removed: 267.4] [added: 272.2] | | | | | | [removed: 263.4] [added: 267.4] | | | | | | [removed: 259.5] [added: 263.4] | | |

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

| Cash and cash equivalents | | | $ | [removed: 7] [added: 13] | | | | | $ | [removed: 25] [added: 7] | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

February 18, 2026

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

February 18, 2026

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

| Dividends on common stock | | | (768) | | | | | | (714) | | | | | | (662) | | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

| Nuclear decommissioning trust fund | | | 1,526 | | | | | | 1,342 | | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

| Amortization of nuclear fuel | | | 56 | | | | | | 81 | | | | | | 68 | | |

| Nuclear fuel expenditures | | | (46) | | | | | | (91) | | | | | | (174) | | |

| Purchases of securities – nuclear decommissioning trust fund | | | (440) | | | | | | (584) | | | | | | (266) | | |

| Sales and maturities of securities – nuclear decommissioning trust fund | | | 416 | | | | | | 564 | | | | | | 240 | | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)

| Capital contribution from parent | | | 28 | | | | | | 476 | | | | | | — | | |

| Dividends on common stock | | | (196) | | | | | | — | | | | | | (9) | | |

[Table](#i379db4a35dfd4fdf8d9a48974b14319e_7) [of Contents](#i379db4a35dfd4fdf8d9a48974b14319e_7)