UELMO 10-K & 10-Q changes, risk factors and insider trading

We are subject to federal, state, and local regulation. The extensive regulatory frameworks, some of which are more specifically identified in the following risk factors, regulate, among other matters, the electric and natural gas utility industries; the rate and cost structure of utilities, including an allowed ROE; the operation of nuclear power plants; the construction and operation of generation, transmission, and distribution facilities; the acquisition, disposal, depreciation and amortization of assets and facilities; the electric transmission system reliability; and wholesale and retail competition. 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 reinterpretationnew interpretations of suchexisting regulations, as well 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 current federalpresidential administration’s approach to Unitedenvironmental Statesand 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. Failure to obtain adequate rates or regulatory approvals in a timely manner; failure to obtain necessary licenses or permits from regulatory authorities; the impact of new or modified laws, regulations, standards, interpretations, or other legal requirements; or increased compliance costs could adversely affect our results of operations, financial position, and liquidity.

Ameren Missouri’s electric and natural gas utility rates and Ameren Illinois’ natural gas utility rates are typically established in regulatory proceedings that take up to 11 months to complete. Ameren Missouri’s electric and natural gas utility rates established in those proceedings are based on historical costs, revenues, and sales volumes. 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 Illinois’ natural gas rates established in those proceedings are based on estimated future costs, revenues, and sales volumes. Effective for rates in 2024 through at least 2027, Ameren Illinois’ electric distribution rates have been established through an MYRP as discussed in the following risk factor. An MYRP includes a revenue requirement reconciliation, which may not allow for full recovery of actual costs due to a reconciliation cap. Thus, the rates that we are allowed to charge for utility services may not match our actual costs at any given time.

Rates include an allowed return on investments established by the regulator, including a return at the applicable WACC on rate base, and an amount for income taxes based on the currently applicable statutory income tax rates and amortization associated with excess deferred income taxes. Although rate regulation is premised on providing an opportunity to earn a reasonable rate of return on rate base, there can be no assurance that the regulator will determine that our costs were prudently incurred or that the regulatory process will result in rates that will produce full recovery of such costs or provide for an opportunity to earn a reasonable return on those investments. Ameren Missouri and Ameren Illinois, and the utility industry generally, have anexperienced increasedhigher needmaintenance for cost recoverycosts and capital expenditures to earnoperate atheir returnelectric, onnatural investments,gas, primarilyand driventransmission by capital investments,businesses, which ishas likelyled to continueincreases in thecustomer future.rates The resulting increase toand the related revenue requirementrequirements needed to recover such costs and earn a return on investmentsinvestments. This could result in more frequent regulatory rate reviews and requests for cost recovery mechanisms. Additionally, increasing rates could result in regulatory or legislative actions, as well as competitive or political pressures, all of which could adversely affect our results of operations, financial position, and liquidity.

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

The CEJA resulted in changesPursuant to the regulatory framework applicable to Ameren Illinois’ electric distribution business by givingCEJA, Ameren Illinois has the option to fileestablish electric distribution rates through an MYRP with the ICC or establish rates through a traditional regulatory rate review, among other things.review. An MYRP establishes rates for a four-year period, and Ameren Illinois has the option to file for an MYRP every four years. Ameren Illinois elected to file an MYRP for rates effective in 2024 through 2027. Under the MYRP, Ameren Illinois is allowed to reconcile its actual electric distribution revenue requirement, as adjusted for certain cost variations, to the ICC-approved revenue requirement on an annual basis, subject to a reconciliation cap. The reconciliation cap limits the annual adjustment to 105% of the annual revenue requirement approved by the ICC. Certain variations from forecasted costs are excluded from the reconciliation cap, including those associated with major storms; new business and facility relocations; changes in the timing of certain expenditures or investments into or out of the applicable calendar year; and changes in interest rates, income taxes, taxes other than income taxes, pension and other post-retirement benefits costs, and amortization of certain assets. The reconciliation cap also excludes costs recovered outside of base rates through riders. The actual revenue requirement for a particular year incorporates Ameren Illinois’ year-end rate base and actual capital structure for such year, provided that the resulting revenue requirement does not exceed the 105% reconciliation cap and the common equity ratio in such capital structure may not exceed that approved by the ICC in the MYRP. Ameren Illinois’ existing riders continue to be effective under the MYRP. In addition, the ICC determines the ROE applicable to each year of the four-year period. Economic conditions could result in the annual predetermined ROE becoming inadequate over the four-year period. Ameren Illinois has filed an appeal of the ICC-determined ROE for 2024 through 2027 to the Illinois Appellate Court for the Fifth Judicial District. For additional information on the appeal see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report. Failure to limit capital expenditures and operation and maintenance expenses to amounts that maintain revenue requirements under the reconciliation cap limit would adversely affect Ameren’s and Ameren Illinois’ results of operations, financial position, and liquidity.

Pursuant to athe Missouri law,PPRA, Ameren Missouri’s PISA election was extended through December 20282035 and an additional extension through December 20332040 is allowed if requested by Ameren Missouri and approved by the MoPSC, among other things.MoPSC. This law also establishedreduced a 2.5%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. The limitationannual islimit effectivein effect was 2.5% and changed to 2.25%, prorated monthly, for revenue requirements approved by the MoPSC after JanuaryAugust 1, 2024.2025. Increased capital expenditures could cause incremental PISA deferrals to exceed the 2.5%2.25% limitation, and such amounts exceeding the 2.5%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 2.5%2.25% limitation could adversely affect Ameren’s and Ameren Missouri’s results of operations, financial position, and liquidity.

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 safety, including permitting programs implemented by federal, state, and local authorities. Such environmental laws regulate air emissions; protect water bodies; manageregulate the handling and disposal of hazardous substances and waste materials; establish siting and land use requirements; and potentialprotect against ecological impacts. Complex and lengthy processes are required to obtain and renew approvals, permits, and licenses for new, existing, or modified energy-related facilities. Additionally, the use and handling of various chemicals orand hazardous materials require release prevention plans and emergency response procedures. Further, we are subject to risks from changing or conflicting interpretations of existing laws, modifications to existing laws, new laws, new or modified permit terms, and enforcement of environmental laws and permits by federal, state, and local authorities.

Environmental regulations have a significant impact on the electric utility industryindustry, and compliance with these regulationsobligations could be costly for Ameren Missouri, which operates coal-fired and natural gas-fired energy centers. As of December 31, 2024,2025, Ameren Missouri’s coal-fired energy centers represented 6%5% and 11% of Ameren’s and Ameren Missouri’s rate base, respectively. Compliance obligations under the Clean Air Act includestem from a variety of programs including the NSPS, the MATS, emission allowance programs andprograms, 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 emissions.emissions, Regulationsalthough implementingthe scope of covered pollutants can change. To the extent our operations impact surface water bodies, including wetlands, the Clean Water Act governrequires potential impacts from our operations on water bodies including wetlands subject to the Act,permitting as well as evaluation of the ecological and biological impact of those operations. Implementation of requirements under the Clean Air Act and the Clean Water Act requirements typically occurs through the issuance of permits by state regulators or resource agencies, and capital expenditures associated with compliance could be significant. Coal-firedThe management and disposal of coal ash from our coal-fired energy centers must comply with managementfederal andregulations disposalknown requirementsas forthe coalCCR ashRule issued under the Resource Conservation and Recovery Act and federal regulations known asrequire the CCRclosure Rule.of Surfacesurface impoundments at Ameren Missouri’sour coal-fired energy centers arealong subject to closure andwith groundwater monitoring requirements and the implementations of corrective measures if necessary. The individual or combined effects of compliance with existing and newfuture environmental regulations could result in significant capital expenditures, increased operating costs, orand the potential for closure or alteration of operations at some of Ameren Missouri’s energy centers.

Currently as required by the CEJA, Ameren Missouri's natural gas-fired energy centers in Illinois are subject to annual limits on emissions, including CO2 and NOx. Further reductions to emissions limits will become effective between 2030 and 2040, resulting in the 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 Illinois,Illinois and will result in their closure by 2040. These energy centers are utilized to support peak loads. Subject to conditions in the CEJA, these energy centers may be allowed to exceed the emissions limits in order to maintain reliability of electric utility service.

We are subject to business and financial risks related to the impact of climate changeclimate-related legislation, regulation, and emission reduction initiatives.

There is concern and activism among various external stakeholders, both nationally and internationally, about climateclimate-related change,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. Also, state and local authorities have proposed restrictions on the use of natural gas, and the ICC is conducting a future of gas proceeding to explore issues involved with decarbonization of the natural gas distribution system in the state of Illinois. Further, federal, state, and local authorities, including the United States Congress,authorities have considered initiatives to further restrict greenhouse gases to address global climateclimate-related change, and the EPA previously announced plans to implement new climate change programs, including regulation of greenhouse gas emissions from the utility industry.risks. Additionally, international agreements have in the past, and could again, lead to future federal or state legislation or regulations. In 2015, the United Nations Framework Convention on Climate Change reached consensus among approximately 190 nations on an agreement, known as the Paris Agreement, that establishes a framework for greenhouse gas mitigation actions by all countries, with a goal of holding the increase in global average temperature to below 2 degrees Celsius above pre-industrial levels and an aspiration to limit the increase to 1.5 degrees Celsius. In accordance with the new presidential administration’s approach to United States energy policy, in January 2025, theThe United States withdrew from the Paris Agreement.Agreement and the United Nations Framework Convention on Climate Change in January 2025 and 2026, respectively. The currentEPA federalhas administration is expected to review,revised, and has alreadyproposed revised,revisions to, compliance requirements under a number of federal environmental regulatory programs related to greenhouse gases; however, differences in energy policy priorities adopted by future federalpresidential administrations could result in additional greenhouse gas reduction requirements in the United States.

As a result of our diverse fuel portfolio, our emissions of greenhouse gases vary among our energy centers, but coal-fired power plants are significant sources of CO2 emissions. Future federal and state legislation or regulations that mandate limits on the emission of, or impose taxation on, greenhouse gases could result in a significant increase in capital expenditures and operating costs, decreased revenues, penalties or fines, or reduced operations of some of Ameren Missouri’s coal- and natural gas-fired energy centers, which, in turn, could lead to increased liquidity and financing needs, and higher financing costs. Moreover, to the extent Ameren Missouri requests recovery of these costs through rates, its regulators might deny some or all of, or defer timely recovery of, these costs. Excessive costs to comply with future legislation or regulations related to climateclimate-related changerisks 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. As a result, mandatory limits could have a material adverse impact on Ameren’s and Ameren Missouri’s results of operations, financial position, and liquidity.

Ameren is targeting net-zero carbon emissions by 2045, as well as a 60% reduction by 2030 and an 85% reduction by 2040 based on 2005 levels in a safe, reliable, and affordable manner. Ameren’s goals include both reduction of direct emissions from operations (scope 1), as well as electricity usage at Ameren buildings (scope 2), including other greenhouse gas emissions of methane, nitrous oxide, and sulfur hexafluoride. 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 and energy prices; operational performance of low- to zero-carbon resources; new transmission infrastructure; the ability to maintain system reliability; duringcustomer anddemand after the transition to cleanfor energy generationincluding carbon-free energy; and constructive energy and economic policies, including those that address investment in energy infrastructure, global climateclimate-related change,risks, incentives for clean energy technologies, and environmental regulations. Additional factors associated with operational risks for the construction and acquisition of electric and natural gas infrastructure may also affect the achievement of these goals, as further discussed below. 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 resourcesresources, 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 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 requiredissued by the NERC. As owners and operators of bulk power transmission systems and electric energy centers, we are subject to mandatory NERC reliability standards, including cybersecurity standards. In addition, our natural gas transmission, distribution, and storage facilities systems are subject to PHMSA rules and regulations. Compliance with these reliability standards, rules, and regulations may subject us to higher operating costs and may result in increased capital expenditures. We may also incur higher operating costs to comply with potential new executive orders, regulations, or reinterpretationsinterpretations of existing regulations issued by these regulatory bodies. If we were found not to be in compliance with these mandatory NERC reliability standards, PHMSA rules and regulations, or FERC regulations, rules, and orders, we could incur substantial monetary penalties and other sanctions, which could adversely affect our results of operations, financial position, and liquidity. The FERC can impose civil penalties of approximately $1.6 million per violation per day for violation of its regulations, rules, and orders, including mandatory NERC reliability standards. The FERC also conducts audits and reviews of Ameren Missouri’s, Ameren Illinois’, and ATXI’s accounting records to assess the accuracy of their respective formula ratemaking process, and it can require refunds to be issued to customers for previously billed amounts, with interest.

Our ability to complete construction projects successfully within projected estimates, including schedule, performance, and/or cost, and to implement Ameren Missouri’s Smart Energy Plan, which may include acquisition of generation facilities after they are constructed, is contingent upon many factors and subject to substantial risks. 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 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 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 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 or battery storage and acquire or construct thatthose generationresources at a reasonable cost; the ability to 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 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 reliability during and after the transition to clean energy generation; new and/or changes in environmental regulations, including those related to CO2 and other greenhouse gas emissions; energy prices; and demand. 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.

•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 obligationsobligations, 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, 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 climateclimate-related change,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 capacity, such as the 2024 collapse of three turbines at the High Prairie Energy Centercapacity; 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;

•the occurrence of catastrophic events such as fires, explosions, acts of sabotage, which 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;

•failure to keep pace with and the ability to adapt to rapid technological changechange, including generative and agentic artificial intelligence; and

Ameren Missouri owns and operates coal-fired energy centers. AboutApproximately 97%96% of Ameren Missouri’s coal is purchased from the Powder River Basin in Wyoming, which has a limited number of suppliers. Deliveries from the Powder River Basin have occasionally been restricted because of rail congestion, staffing and equipment issues, infrastructure maintenance, derailments, weather, and supplier financial hardship. As of December 31, 2024,2025, coal inventory was near targeted levels at the Labadie Energy Center and Sioux energy centers were at targeted levels.levels at the Sioux Energy Center. Delays or disruptions in the delivery of coal, failure of our coal suppliers to provide adequate quantities or quality of coal, or lack of adequate inventories of coal, including low-sulfur coal used to comply with environmental regulations, could have adverse effects on Ameren Missouri’s electric generation operations. If Ameren Missouri is unable to obtain an adequate supply of coal under existing agreements, it may be required to purchase coal at higher prices or be forced to reduce generation at its coal-fired energy centers, which could adversely affect Ameren’s and Ameren Missouri’s results of operations, financial position, and liquidity.

Our aging infrastructure may pose risks to system reliability and expose us to expedited or unplanned significant capital expenditures and operating costs. Both of Ameren Missouri’s coal-fired energy centers were constructed prior to 1978, and the Callaway Energy Center began operating in 1984. The age of these energy centers increases the risks of unplanned outages, reduced generation output, and higher maintenance expense. Further, 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. Aging transmission and distribution facilities are more prone to failure than new facilities, which results in higher maintenance expense and the need to replace these facilities with new infrastructure. Even when the system is properly maintained, its reliability may ultimately deteriorate and negatively affect our ability to serve our customers, which could result in increased costs subject to regulatory recovery risk. The frequency and duration of customer outages are among the CEJA performance standards. Any failure to achieve these standards will result in a reduction in Ameren Illinois’ allowed ROE on electric distribution assets. The higher maintenance costs associated with aging infrastructure and capital expenditures for new or replacement infrastructure, compounded by high interest rates and inflationary pressures,infrastructure could cause additional rate volatility and increases for our customers, resistance by our regulators to allow customer rate increases, and/or regulatory lag in some of our jurisdictions, any of which could adversely affect our results of operations, financial position, and liquidity.

Forecasted energy demand from potential new customers and electrification might not be realized. Energy conservation, energy efficiency, distributed generation, energy storage, technological advances, and other factors could reduce energy demand from our existing customers.

Ameren is a holding company; therefore, its primary assets are its investments in the common stock of its subsidiaries, including Ameren Missouri, Ameren Illinois, and ATXI. As a result, Ameren’s ability to pay dividends on its common stock depends on the earnings of its subsidiaries and the ability of its subsidiaries to pay dividends or otherwise transfer funds to Ameren. Similarly, Ameren’s ability to service its debt obligations is dependent upon the earnings of its operating subsidiaries and the distribution of those earnings and other payments, including payments of principal and interest under affiliate indebtedness. The payment of dividends to Ameren by its subsidiaries in turn depends on the subsidiaries’ results of operations, and other items affecting retained earnings, and available cash. Ameren’s subsidiaries are separate and distinct legal entities and have no obligation, contingent or otherwise, to pay any dividends or make any other distributions (except for payments required pursuant to the terms of affiliate borrowing arrangements and cash payments under the tax allocation agreement) to Ameren. Under the IRA, a 15% minimum tax on adjusted financial statement income, as defined in the law, is assessed against corporations whose average annual adjusted financial statement income exceeds $1 billion for three consecutive preceding tax years effective for tax years beginning after December 31, 2022.years. Once a corporation exceeds this three-year average annual adjusted financial statement income threshold, it will be subject to the minimum tax for all future tax years. As Ameren is a holding company and files a consolidated income tax return, it is reliant on its subsidiaries to pay the minimum tax once the threshold is exceeded. The payments related to the minimum tax by Ameren Missouri, Ameren Illinois, and ATXI are expected to be recovered, subject to approval by their respective regulators. In addition, interpretations, regulations, amendments, or technical corrections that affect the amount and timing of income tax payments, credits available, or the transferability of production and investment tax credits could adversely affect our liquidity. Certain financing agreements, corporate organizational documents, and certain statutory and regulatory requirements may impose restrictions on the ability of Ameren Missouri, Ameren Illinois, and ATXI to transfer funds to Ameren in the form of cash dividends, loans, or advances.

A part of our core strategy focuses on disciplined cost management, including prudently monitoring all of our expenses. Higher than expected inflation levels could continue to put pressure on the prices of labor, services, materials and supplies, and other costs. ElevatedHigher inflation levels, as well as elevatedhigher interest rates, tariffs, trade wars, or a recession could impact our ability to control costs, to make substantial investments in our businesses, to recover costs and investments, to earn our allowed ROEs within frameworks established by our regulators, and/or to maintain affordability of our services for our customers. In addition, these various economic pressures could adversely affect our customers’ usage of, or payment for, our services. Additionally, volatility in the commodities market could increase collateral postings and prepayments. Also, market volatility could significantly affect the investment performance of Ameren’s COLI. Significant increases in our costs could increase our financing needs and otherwise adversely affect our results of operations, financial position, and liquidity.

Related to benefits, Ameren has defined benefit pension plans covering substantially all of its employees and has postretirement benefit plans covering non-union employees hired before October 2015 and union employees hired before January 2020. Assumptions related to future costs, returns on investments, interest rates, timing of employee retirements, and mortality, as well as other actuarial matters, have a significant impact on our customers’ rates and our plan funding requirements. Ameren’s total pension and postretirement benefit plans were overfunded by $734$954 million as of December 31, 2024.2025. Ameren expects to fund its pension plans at a level equal to the greater of the pension cost or the legally required minimum contribution. Based on its assumptions at December 31, 2024,2025, its investment performance in 2024,2025, and its pension funding policy, Ameren does not expect to make material contributions in 2025 and expects to make aggregateannual contributions of $170approximately $45 million to $50 million in 2026each throughof 2029.the next five years, with aggregate estimated contributions of $240 million. Ameren Missouri and Ameren Illinois estimate that their portion of the future funding requirements will be 40%35% and 50%,45%, respectively. These estimated contributions may change based on actual investment performance, changes in interest rates, changes in our assumptions, changes in government regulations, and any voluntary contributions. In addition to the costs of our pension plans, the costs of providing health care benefits to our employees and retirees have increased in recent years. We believe that our employee benefit costs, including costs of health care plans for our employees and former employees, will continue to rise. Future legislative changes related to health care could also significantly change our benefit programs and costs.

Our results are influenced by the expectations of our customers, investors, legislators, regulators, creditors and ratings agencies. Those expectations are based, in part, on the reliability and affordability of our utility services. Service interruptions and facility shutdowns can occur due to failures of equipment as a result of severe or destructive weather or other causes. The ability of Ameren Missouri and Ameren Illinois to prevent, mitigate, or respond promptly to such failures can affect customer satisfaction or potentially subject us to litigation. In addition to system reliability issues, the success of modernization efforts, our ability to safeguard sensitive customer information and protect our systems from physical or cyber attacks, and other actions can affect customer satisfaction. The level of rates, the timing and magnitude of rate increases, and the volatility of rates can also affect regulator and customer satisfaction. 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.

Our ability to successfully execute our strategic plan, including the transition of Ameren Missouri’s generation fleet that will be included in its 2025 Change to the 2023 PRP, may affect customers’, investors’, legislators’, regulators’, creditors’, and rating agencies’ opinions and actions. Additionally, negative perceptions or publicity resulting from increasing scrutiny of company policies or practices could negatively impact our reputation, investment in our common stock, or our access to capital and credit markets. Customers’, investors’, legislators’, regulators’, creditors’, and rating agencies’ opinions of us can also be affected by media coverage, including social media, which may include information, whether factual or not, that damages our brand and reputation.

Our businesses depend upon our ability to employ and retain key officers and other skilled professional and technical employees. Certain specialized knowledge that focuses on skilled-craft and STEM-related disciplines is required to construct and operate generation, transmission, and distribution assets. Further, a significant portion of our work force is nearing retirement. As of December 31, 2024,2025, approximately 23%22% of Ameren’s, Ameren Missouri’s, and Ameren Illinois’ total employees were 55 years old or older. We are also party to collective bargaining agreements that collectively represent about 46%, 59%,58%, and 55%54% of Ameren’s, Ameren Missouri’s and Ameren Illinois’ total employees, respectively. The Ameren Missouri collective bargaining unit contracts expire in 20252026 and 2026,2028, and cover 4%96% and 96%4% of represented employees, respectively. The Ameren Illinois collective bargaining unit contracts expire in 20262027 and 2027,2029, and cover 92%8% and 8%92% of represented employees, respectively. 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. Certain events, such as significant delays in finding appropriate replacement talent, inadequately trained replacement employees, a mismatch of skill sets to future needs, or any work stoppage experienced in connection with negotiations of collective bargaining agreements could adversely affect our operations.

There has been an increase in the number and sophistication of physical and cyber attacks across all industries worldwide. Physical attacks could include sabotaging, vandalizing, or burglarizing transmission and distribution facilities, which are unmanned, widely dispersed, and often in isolated areas, or the theft of physical data and information. Cyber attacks could include viruses, malicious or destructive code, phishingsocial or quishingengineering attacks, denial of service attacks, supply chain attacks, ransomware and other extortion-based attacks, improper access by third parties, attacks on email systems, and attacks leading to data loss, including data stored using cloud technologies, operational control, or exploitation of vulnerabilities specific to internally developed systems or to those provided and/or maintained by our suppliers,suppliers. includingThis thosealso includes attacks arising from or generated by artificial intelligence, among various other attempts to compromise systems that can lead to security breaches. In addition, the increasingly widespread adoption of artificial intelligence technologies, including generative and agentic artificial intelligence, may increaseincrease, accelerate, or enhance cyber attacks and other operational, legal, privacy, and reputational risks in our industry and worldwide. Also, remote working arrangements could increase our data security risks, including loss of data related to sensitive customer, employee, financial, and operating system information, through insider or outsider actions. A security breach of our physical assets or in our information systems could affect the reliability of the transmission and distribution system, disrupt electric generation, including nuclear generation, and/or subject us to financial harm resulting from theft or the inappropriate release or destruction of certain types of information, including sensitive customer, employee, financial, and operating system information. Many of our suppliers, vendors, contractors, and information technology providers leverage systems that support our operations and maintain customer and employee data. An interruption of these third-party systems could adversely affect our business as if it was a disruption of our own system. If a significant breach or other interruption occurred, whether due to an intentional or unintentional act, our reputation could be adversely affected, customer confidence could be diminished, availability of our services could be impacted, and/or we could be subject to increased costs associated with regulatory oversight, fines or legal claims, any of which could result in a significant decrease in revenues or significant costs for remedying the impacts of such a disruption. Our generation, transmission, and distribution systems are part of an interconnected grid. Therefore, a breach or other disruption caused by a physical or cyber incident at another utility, electric generator, RTO, or commodity supplier could also adversely affect our businesses. Insurance might not be adequate to cover losses that arise in connection with these events. In addition, new regulations could require changes in our security measures and result in increased costs. The occurrence of any of these events could adversely affect our results of operations, financial position, and liquidity.

We rely on the issuance of short-term and long-term debt and equity as significant sources of liquidity and funding for capital requirements not satisfied by our operating cash flow, as well as to refinance existing long-term debt. The inability to raise debt or equity capital on reasonable terms, or at all, could negatively affect our ability to maintain or to expand our businesses. General economic factors beyond our control might create uncertainty that could increase our cost of capital or impair or eliminate our ability to access the debt, equity, or credit markets, including our ability to draw on bank credit facilities. 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 instability, war, terrorism, and extreme volatility in the debt, equity, or credit markets. In addition, volatility in stock prices of perceived significant energy consumers, such as technology companies involved with artificial intelligence or cryptocurrency, or other significant developments with such companies, could cause increased volatility in stock prices of energy utility companies such as Ameren. Any adverse change in our credit ratings could reduce access to capital and trigger collateral postings and prepayments. Such changes could also increase the cost of borrowing and the costs of fuel, power, and natural gas supply, among other things, which could adversely affect our results of operations, financial position, and liquidity.

Our core strategy is driven by the following three pillars, which allow us to capitalizedeliver on opportunities to benefit our customers, communities, shareholders, and the environmentshareholders:

In February 2025,2026, 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 2025.2026. The plan is designed to upgrade Ameren Missouri’s electric infrastructure and includes investments that will upgrade the grid and accommodate more renewable energy. Investments under the plan are expected to total approximately $16.2$20.8 billion over the five-year period from 20252026 through 2029,2030, with expenditures largely recoverable under the PISA. 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. See Note 14 – Commitments and Contingencies under Part II, Item 8, of this report, for additional information on the EPA regulations. The Smart Energy Plan excludes investments in its natural gas distribution business, as well as removal costs, net of salvage.

In December 2024,2025, the ICC issued an order approving Ameren Illinois’ 20232024 electric distribution service revenue requirement reconciliation adjustment filing. This order approved a reconciliationan adjustment ofincreasing $158the allowed revenue requirement by $48 million, which reflected Ameren Illinois’ actual 20232024 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 2025.2026. In February 2026, the ICC denied Ameren Illinois’ rehearing request to include an asset associated with other postretirement benefits in the rate base, among other things. 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.

Ameren has an ATM program under which Ameren may offer and sell from time to time common stock, including under its ATM program, which includes the ability to enter into forward sale agreements, subject to market conditions and other factors. As of December 31, 2024,2025, Ameren had approximately $550$1.5 millionbillion of common stock remaining available for sale under the ATM program,program. whichAs takesof intoDecember account31, the2025, Ameren had multiple forward sale agreements inwith effectvarious ascounterparties relating to 6.4 million shares of Decembercommon 31,stock, 2024.which it expects to settle in 2026. For information regarding long-term debt issuances and maturities, common stock issuances, and outstanding forward sale agreementsagreements, enteredincluding intothose under the ATM programprogram, through the date of this report, see Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of this report.

(b)Amounts include the MISO long-range transmission projects assigned to Ameren, as well as the first tranche competitive projects awarded to ATXI discussed above.ATXI.

Net income attributable to Ameren common shareholders in 20242025 increased $30$274 million, and $0.04$0.93 per diluted share, from 2023.2024. The increase was due to net income increases of $27$188 million, $15$92 million, $47 million, and $14$9 million at Ameren Missouri, Ameren Transmission, Ameren Illinois NaturalElectric Gas,Distribution, and Ameren Missouri,Illinois Natural Gas, respectively. TheThese increases in net income were partially offset by a net income decrease of $24 million at Ameren Illinois Electric Distribution and an increase in the net loss of $62 million for activity not reported as part of a segment, primarily at Ameren (parent), of $2 million..

Earnings per diluted share in 2024,2025, compared with 2023,2024, were favorably affected by:

•increased base rate revenues at Ameren Missouri effective JulyJune 9,1, 2023,2025, pursuant to the JuneApril 20232025 MoPSC electric rate order,order and a lower base level of expenses, partially offset by the net effect of amortization of previously deferred depreciation expense under the PISA and RESRAM, financing costs otherwise recoverable under the PISA and RESRAM, adepreciation lowerand baseamortization levelon ofproperty, expensesplant, includedand inequipment trackers,previously eligible for deferral under the PISA and RESRAM, and the net recovery for amounts associated with the reduction in sales volumes resulting from MEEIA programs (942 cents per share);

•increased retail electric sales volumes at Ameren Missouri, excluding customer energy-efficiency programs, primarily due to higherwarmer July temperatures and colder winter temperatures, and growth in weather-normalized retail electric sales excluding customer energy-efficiency programs (estimated at 822 cents per share);

•the absence of a 2024 charge recorded by Ameren Missouri, included in other operation and maintenance expenses, related to ana ordersettlement fromagreement with the United States District Court for the Eastern DistrictDepartment of Missouri,Justice whichthat resolved all outstanding claims in the NSR and Clean Air Act litigation related to the Rush Island Energy Center, see Note 14 - Commitments and Contingencies under Part II, Item 8, of this report for moreadditional information (17 cents per share);

•lowerincreased revenuerate base investments at Ameren Transmission and Ameren Illinois Electric Distribution due to a lower recognized ROE under the MYRP (914 cents per share);

•the resultabsence of the October 2024 FERC order reducing the allowed base ROE for FERC regulated transmission rate base and required refunds for certain prior periods under the MISO tariff, which decreasedincreased Ameren Transmission earnings (4 cents per share); and

(e)Electric and natural gas revenue changes are offset by corresponding changes in “Fuel and purchased power” and “Natural gas purchased for resale” on the statement of income. Activity in Other/Intersegment Eliminations of $12$41 million representswas thedue changes in eliminations of related-party transactions between Ameren Missouri, Ameren Illinois, and ATXI (-$6 million), as well asto changes in Ameren Transmission revenue from transmission services provided to Ameren Illinois Electric Distribution (-$6-$41 million). See Note 13 – Related-party Transactions and Note 16 – Segment Information under Part II, Item 8, of this report for additional information on intersegment eliminations. These items have no overall impact on earnings.

Ameren’s electric revenues increased $101$1,128 million, or 2%,17%, in 2024,2025, compared with 2023,2024, due to increased revenues at Ameren MissouriMissouri, Ameren Illinois, and Ameren Transmission, partially offset by decreased revenues at Ameren Illinois Electric Distribution, as discussed below.

Ameren Transmission’s electric revenues increased $104$81 million, or 15%,10%, in 2024,2025, compared with 2023.2024. Revenues were favorably affected by higher recoverable expenses (+$55$47 million), and increased capital investment (+$44$24 million), as evidenced by a 15%7% increase in rate base used to calculate the revenue requirement,requirement. and increased facility rentalAdditionally, revenues (+$15 million) related to ATXI’s transmission operations control center, which was placed in service in December 2023. ATXI provides affiliates with access to this facility. Rental revenues associated with this facility are affiliate transactions and eliminated in consolidation for Ameren’s consolidated financial statements. See Note 13 – Related-party Transactions under Part II, Item 8, of this report for additional information. Revenues were unfavorablyfavorably affected by a decrease in the allowedabsence base ROE under the MISO tariff resulting fromof the October 2024 FERC order,order whichthat includeddecreased customerbase refundsROE for certain historical periods (-$10+$10 million). See Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report for additional information regarding the FERC complaint cases.

Net income attributable to Ameren common shareholders in the three months ended MarchJune 31,30, 2026, was $357$314 million, or $1.28$1.13 per diluted share, compared with $289$275 million, or $1.07$1.01 per diluted share, in the year-ago period. Net income attributable to Ameren common shareholders in the six months ended June 30, 2026, was $671 million, or $2.41 per diluted share, compared with $564 million, or $2.08 per diluted share, in the year-ago period. Net income was favorably affected for the three and six months ended MarchJune 31,30, 2026, by increased infrastructure investments across all segments, including infrastructure reflected in electric and natural gas service rates at Ameren Missouri, effective June 1, 2025 and September 1, 2025, respectively, and natural gas rates at Ameren Illinois, effective December 2, 2025. Net income was unfavorably affected for the three and six months ended MarchJune 31,30, 2026, by decreasedincreased retailother electricoperations salesand volumesmaintenance expenses at Ameren Missouri,Missouri primarilynot subject to riders or trackers, largely due to warmerhigher winterenergy temperaturescenter maintenance expense and an increase in 2026,vegetation management expenses, among other items.

Ameren’s strategic plan includes investing in rate-regulated energy infrastructure, enhancing regulatory frameworks and advocating for responsibleenergy policies, and optimizing operating performance to deliver onsafe, opportunitiesreliable, toaffordable benefitenergy for our customers, communities,customers and shareholders.communities. Ameren remains focused on disciplined cost management and strategic capital allocation. Ameren invested $1.6$2.7 billion in its rate-regulated businesses in the threesix months ended MarchJune 31,30, 2026.

In 2026, Ameren Missouri executed electric service agreements with large load customers under its modified large primary service tariff that was approved in 2025, representing 2.8 gigawatts of demand.demand that is expected to begin materializing in the second half of 2027 and to reach full capacity by the end of 2029. 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 December 2024, the ICC issued an order in connection with a revised Grid Plan and a revised MYRP filed by Ameren Illinois in March 2024, approving revenue requirements for electric distribution services for 2024 through 2027 of $1,206 million, $1,287 million, $1,367 million, and $1,421 million, respectively. Rate changes consistent with the December 2024 order became effective in December 2024. In MarchMay 2025, Ameren Illinois filed an appeal of the ICC’s December 2024 order to2026, the Illinois Appellate Court for the Fifth Judicial District to reviseupheld the allowedICC’s ROEDecember 2024 order and to include an asset associated with other postretirement benefits in the rate base, among other things. In addition, Ameren Illinois filed an appeal related to orders issued by the ICC in June 2024 and December 2023 andfollowing Juneappeals 2024by relatedAmeren to the MYRP proceeding. The appellate court is under no deadline to address the appeals.Illinois.

In December 2025, the ICC issued an order approving Ameren Illinois’ 2024 electric distribution service revenue requirement reconciliation adjustment filing. This order approved an adjustment increasing the allowed revenue requirement by $48 million, which reflected Ameren Illinois’ actual 2024 recoverable costs, year-end rate base of $4.2 billion, and capital structure composed of 50% common equity. The approved reconciliation adjustment is being collected from customers in 2026. In March 2026, Ameren Illinois filed an appeal of the December 2025 order with the Illinois Appellate Court for the Fifth Judicial District.District Theand withdrew the appeal in July 2026 as a result of the appellate court isdecision under no deadline to addressin the appeal.MYRP proceeding discussed above.

In April 2026, Ameren Illinois filed a reconciliation adjustment to its 2025 electric distribution service revenue requirement with the ICC,ICC. requestingIn June 2026, the ICC staff filed its calculation of the reconciliation adjustment, recommending recovery of $65$31 million. In July 2026, Ameren Illinois filed a revised reconciliation adjustment consistent with the ICC staff's recommendation. The adjustment reflects Ameren Illinois’ actual 2025 recoverable costs, 2025 year-end rate base, which includes assets associated with other postretirement benefits that are under appeal in Ameren Illinois’ MYRP and 2024 electric distribution service revenue requirement reconciliation adjustment proceedings,base and a capital structure composed of 50% common equity. An ICC decision is required by December 2026, and any approved adjustment would be collected from customers in 2027.

The following table presents a summary of Ameren’s earnings for the three and six months ended MarchJune 31,30, 2026 and 2025:

Net income attributable to Ameren common shareholders increased $68$39 million and earnings per diluted share increased 2112 cents in the three months ended MarchJune 31,30, 2026, compared with the year-ago period. The increase was due to net income increases of $34$10 million, $14 million, $9million,$7 million, and $3$6 million,million at Ameren Missouri,Transmission, Ameren Illinois Natural Gas, Ameren TransmissionMissouri, and Ameren Illinois Electric Distribution, respectively. Additionally,The thereabove increases were partially offset by a $1 million reduction in net income at Ameren Illinois Natural Gas. Net income was further impacted by a decrease in net loss of $8$17 million for activity not reported as part of a segment, primarily at Ameren (parent).

Earnings per diluted share were favorably affected in the three and six months ended MarchJune 31,30, 2026, compared to the year-ago period,periods (except where a specific period is referenced), by:

•a higher allowance for equity funds used during construction and increased base rate revenues at Ameren Missouri for the inclusion of previously deferred interest charges under PISA pursuant to the April 2025 MoPSC electric rate order, partially offset by lower interest deferrals associated with the PISA (78 cents and 15 cents per shareshare, respectively);

•increased base rate revenues at Ameren Missouri’s natural gas business,Missouri, pursuant to the JulyApril 2025 MoPSC natural gaselectric rate order, effective SeptemberJune 1, 2025, partially offset by higher depreciation and amortization and interest expenses included in base rates (34 cents and 12 cents per shareshare, respectively).;

Earnings per diluted share were unfavorably affected in the three and six months ended MarchJune 31,30, 2026, compared to the year-ago period,periods by:

•increased other operations and maintenance expenses at Ameren Missouri not subject to riders or trackers, largely due to higherincreased reliability measures at the Labadie and Sioux energy center maintenance expensecenters and an increase in injuriestransmission and damagesdistribution vegetation management expenses, partially offset by a decrease in storm-related costs compared to the year-ago period (311 cents and 14 cents per shareshare, respectively); and

•increased weighted-average basic common shares outstanding resulting from issuances of common shares (3 cents and 6 cents per shareshare, respectively).;

The cents per share variances above are presented based on the weighted-average basic common shares outstanding in the three and six months ended MarchJune 31,30, 2025, and do not reflect the impact of dilution on earnings per share, unless otherwise noted. The amounts above other than variances related to income taxes have been presented net of income taxes using Ameren’s 2026 blended federal and state statutory tax rate of 26%. For additional details regarding the Ameren Companies’ results of operations, including explanations of Operating Revenues for both Electric Revenues and Natural Gas Revenues; Fuel and Purchased Power Expenses; Other Operations and Maintenance Expenses; Depreciation and Amortization Expenses; Taxes Other Than Income Taxes; Other Income, Net; Interest Charges; and Income Taxes, see the major headings below.

Below is Ameren’s table of income statement components by segment for the three and six months ended MarchJune 31,30, 2026 and 2025:

Below is Ameren Illinois’ table of income statement components by segment for the three and six months ended MarchJune 31,30, 2026 and 2025:

The following table presents the increases (decreases) by Ameren segment for electric and natural gas revenues for the three and six months ended MarchJune 31,30, 2026, compared with the year-ago periodperiods:

(a)Includes an increase in transmission revenues of $10$16 million and $26 million at Ameren Illinois for the three and six months ended MarchJune 31,30, 2026, respectively, compared with the year-ago period.periods.

(c)Represents the estimated variation resulting primarily from changes in cooling and heating degree-days on electric and natural gas demand compared with the year-ago periodperiods; this variation is based on temperature readings from National Oceanic and Atmospheric Administration weather stations at local airports in our service territories.

(d)The electric deferred income tax adjustment relates to the remaining balance of certain excess deferred income taxes that were amortized through 2025. Offsetting expense increases or decreases are reflected within the "Income Taxes" section of the statement of income. This item has no overall impact on earnings.

(f)Electric and natural gas revenue changes are offset by corresponding changes in “Fuel and purchased power” and “Natural gas purchased for resale” on the statement of income. For the three and six months ended MarchJune 31,30, 2026, activity in Other/Intersegment Eliminations of $7$6 million and $13 million, respectively, was primarily due to the changes in Ameren Transmission revenue from transmission services provided to Ameren Illinois Electric Distribution (-$7-$5 million and -$12 million, respectively). See Note 14 – Segment Information under Part I, Item 1, of this report for additional information on intersegment eliminations. These items have no overall impact on earnings.

Ameren’s electric revenues increaseddecreased $39$151 million, or 2%,7%, and $112 million, or 3%, for the three and six months ended MarchJune 31,30, 2026, respectively, compared with the year-ago period,periods, primarily due to decreased revenues at Ameren Missouri, partially offset by increased revenues at Ameren Illinois Electric Distribution and Ameren Transmission, partially offset by decreased revenues at Ameren Missouri, as discussed below.

Ameren Transmission’s electric revenues increased $17$21 million, or 8%,10%, and $38 million, or 9%, for the three and six months ended MarchJune 31,30, 2026, respectively, compared with the year-ago period.periods. Revenues were affected by higher recoverable expenses (+$10$12 million and +$22 million, respectively) and increased return on capitalhigher investmentrate base (+$7$9 million and +$16 million, respectively), as evidenced by a 9%10% increase in rate base used to calculate the revenue requirement.

Ameren Missouri’s electric revenues decreased $42$221 million, or 5%,17%, and $263 million, or 12%, for the three and six months ended MarchJune 31,30, 2026, respectively, compared with the year-ago period.periods.

The following items decreased Ameren Missouri’s electric revenues betweenfor periodsthe three and six months ended June 30, 2026:

•“Off-system sales, capacity, transmission, and FAC revenues, net” decreased $145$333 million and $478 million, respectively, primarily due to spring capacity prices decreasing from $720 per MW-day in 2025 to $70 per MW-day in 2026 as a result of the annual MISO auctions.

•The effect of weather decreased revenues an estimated $17$13 million primarilyand $30 million, respectively. This is due to warmer wintermilder temperatures in the first half of 2026.

The following items increased Ameren Missouri’s electric revenues betweenfor periodsthe three and six months ended June 30, 2026:

•Higher electric base rates, excluding the change in base rates for the MEEIA customer energy-efficiency programs and the RESRAM, resulting from the April 2025 MoPSC electric rate order effective June 1, 2025, increased revenues an estimated $74$44 million.million and $118 million, respectively.

•Revenues associated with “Cost recovery mechanisms – offset in fuel and purchased power” increased $27$32 million and $59 million, respectively, due to increased revenue related to the recovery of costs previously deferred under the FAC. The changes to “Cost recovery mechanisms - offset in fuel and purchased power” are fully offset by changes to “Cost recovery mechanisms - offset in electric revenue” in fuel and purchased power.

•Revenues increased $17$9 million and $26 million, respectively, due to the absence of the deferral of base rate revenues to a regulatory liability related to the Rush Island Energy Center following its October 15, 2024 retirement date, in accordance with the June 2024 MoPSC financing order. The deferral ended with new rates effective June 1, 2025.

Ameren Illinois’ electric revenues increased $74$67 million, or 11%,10%, and $141 million, or 10%, for the three and six months ended MarchJune 31,30, 2026, respectively, compared with the year-ago period,periods, driven by increased revenues at Ameren Illinois Electric Distribution and Ameren Illinois Transmission.

Ameren Illinois Electric Distribution’s revenues increased $71$56 million, or 12%,10%, and $127 million, or 11%, for the three and six months ended MarchJune 31,30, 2026, respectively, compared with the year-ago period.periods.

The following items increased Ameren Illinois Electric Distribution’s revenues betweenfor periodsthe three and six months ended June 30, 2026:

•Revenues associated with “Cost recovery mechanisms – offset in fuel and purchased power” increased $54$15 million and $69 million, respectively, due to increased purchased power expenses recovered from customers. The increase in electric revenues are fully offset by an increase in purchased power expenses under cost recovery mechanisms for purchased power, as discussed below.

•Base rates increased revenues by $16$27 million and $43 million, respectively, due to higher recoverable non-purchased power expenses (+$13$24 million and +$37 million, respectively) and increased return on capitalhigher investmentrate base (+$3 million and +$6 million, respectively).