About This Report

Reporting Parameters

Our report follows the spirit of Global Reporting Initiative’s G4 Guidelines and addresses many elements contained in the Electric Utilities Sector Supplement. Our general reporting period is inclusive up to Dec. 31, 2015. Where appropriate, we included historical and/or forward-looking information to provide context and perspective. An internal steering committee oversaw report preparation with guidance from our Corporate Sustainability Council, Executive Leadership Team and internal subject-matter experts. We also engaged outside experts where appropriate.

Use of Non-GAAP Financial Measures

In this report, Ameren has presented core earnings, which is a non-GAAP measure and may not be comparable to those of other companies. A reconciliation of GAAP to non-GAAP results is included either on the page where the non-GAAP measure appears or on another page referenced in this report. Generally, core earnings or losses include earnings or losses attributable to Ameren common shareholders and exclude income or loss from discontinued operations and income or loss from significant discrete items that management does not consider representative of ongoing earnings, such as the second quarter 2015 provision for discontinuing pursuit of a construction and operating license for a second nuclear unit at the Callaway Energy Center. Ameren uses core earnings internally for financial planning and for analysis of performance. Ameren also uses core earnings as the primary performance measurement when communicating with analysts and investors regarding our earnings results and outlook, as the company believes that core earnings allow the company to more accurately compare its ongoing performance across periods. In providing core earnings guidance, there could be differences between core earnings and earnings prepared in accordance with GAAP as a result of our treatment of certain items, such as those described above. Ameren is unable to estimate the impact, if any, on GAAP earnings of any such future items.

Forward-looking Statements

Statements in this report not based on historical facts are considered “forward-looking” and, accordingly, involve risks and uncertainties that could cause actual results to differ materially from those discussed. Although such forward-looking statements have been made in good faith and are based on reasonable assumptions, there is no assurance that the expected results will be achieved. These statements include (without limitation) statements as to future expectations, beliefs, plans, strategies, objectives, events, conditions, and financial performance. In connection with the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, we are providing this cautionary statement to identify important factors that could cause actual results to differ materially from those anticipated. The following factors, in addition to those discussed under Risk Factors in Ameren’s Form 10-K for the year ended Dec. 31, 2015, and elsewhere in this report and in our other filings with the Securities and Exchange Commission, could cause actual results to differ materially from management expectations suggested in such forward-looking statements:

• regulatory, judicial, or legislative actions, including changes in regulatory policies and ratemaking determinations, that may result from the complaint cases filed with the Federal Energy Regulatory Commission seeking a reduction in the allowed base return on common equity under the Midcontinent Independent System Operator, Inc. tariff, Ameren Missouri’s appeal of the method and inputs used to calculate its performance incentive under the Missouri Energy Efficiency Investment Act (MEEIA), and future regulatory, judicial, or legislative actions designed to change regulatory recovery mechanisms;
• the effect of Ameren Illinois participating in a performance-based formula ratemaking process under the Illinois Energy Infrastructure Modernization Act (IEIMA), including the direct relationship between Ameren Illinois’ return on common equity and 30-year United States Treasury bond yields, the related financial commitments required by the IEIMA, and the resulting uncertain impact on Ameren Illinois’ results of operations, financial position, and liquidity;
• our ability to align our overall spending, both operating and capital, with regulatory frameworks established by our regulators in an attempt to earn our allowed return on equity;
• the effects of changes in laws and other governmental actions, including monetary, fiscal, tax, and energy policies;
• the effects of changes in federal, state, or local tax laws, regulations, interpretations, or rates and any challenges to the tax positions taken by the Ameren companies;
• the effects on demand for our services resulting from technological advances, including advances in customer energy efficiency and distributed generation sources, which generate electricity at the site of consumption and are becoming more cost-competitive;
• the effectiveness of Ameren Missouri’s customer energy efficiency programs and the related amount of any revenues and performance incentive earned under the MEEIA plans approved in August 2012 and, February 2016, and under any future approved MEEIA plan;
• the timing of increasing capital expenditure and operating expense requirements and our ability to recover these costs in a timely manner;
• the cost and availability of fuel such as coal, natural gas, and enriched uranium used to produce electricity; the cost and availability of purchased power and natural gas for distribution; and the level and volatility of future market prices for such commodities, including our ability to recover the costs for such commodities and our customers’ tolerance for the related rate increases;
• disruptions in the delivery of fuel, failure of our fuel suppliers to provide adequate quantities or quality of fuel, or lack of adequate inventories of fuel, including ultra-low-sulfur coal used for Ameren Missouri’s compliance with environmental regulations;
• the effectiveness of our risk management strategies and our use of financial and derivative instruments;
• the ability to obtain sufficient insurance, including insurance relating to Ameren Missouri’s Callaway energy center and insurance for cyber attacks, or, in the absence of insurance, the ability to recover uninsured losses;
• business and economic conditions, including their impact on key customers, interest rates, collection of our receivable balances, and demand for our products;
• Noranda Aluminum, Inc.’s (Noranda) bankruptcy filing, the expected curtailment of operations at its aluminum smelter located in southeast Missouri, and the resulting impacts to Ameren Missouri’s ability to recover its revenue requirement;
• revisions to Ameren Missouri’s long-term power supply agreement with Noranda, including Ameren Missouri’s notification to terminate the agreement effective June 1, 2020, and Ameren Missouri’s decision as to whether to seek Missouri Public Service Commission approval to cease providing electricity to Noranda thereafter;
• disruptions of the capital markets, deterioration in credit metrics of the Ameren companies, or other events that may have an adverse effect on the cost or availability of capital, including short-term credit and liquidity;
• the impact of the adoption of new accounting guidance and the application of appropriate technical accounting rules and guidance;
• actions of credit rating agencies and the effects of such actions;
• the impact of weather conditions and other natural phenomena on us and our customers, including the impact of system outages;
• the construction, installation, performance, and cost recovery of generation, transmission, and distribution assets;
• the effects of breakdowns or failures of equipment in the operation of natural gas distribution and transmission systems and storage facilities, such as leaks, explosions and mechanical problems, and compliance with natural gas safety regulations;
• the effects of our increasing investment in electric transmission projects and the uncertainty as to whether we will achieve our expected returns in a timely fashion;
• operation of Ameren Missouri’s Callaway energy center, including planned and unplanned outages, and decommissioning costs;
• the effects of strategic initiatives, including mergers, acquisitions, and divestitures, and any related tax implications;
• the impact of current environmental regulations and new, more stringent, or changing requirements, including those related to carbon dioxide, other emissions and discharges, cooling water intake structures, coal combustion residuals, and energy efficiency, that are enacted over time and that could limit or terminate the operation of certain of our energy centers, increase our costs or investment requirements, result in an impairment of our assets, cause us to sell our assets, reduce our customers’ demand for electricity or natural gas, or otherwise have a negative financial effect;
• the impact of complying with renewable energy portfolio requirements in Missouri;
• labor disputes, work force reductions, future wage and employee benefits costs, including changes in discount rates, mortality tables, and returns on benefit plan assets;
• the inability of our counterparties to meet their obligations with respect to contracts, credit agreements, and financial instruments;
• the cost and availability of transmission capacity for the energy generated by Ameren Missouri’s energy centers or required to satisfy Ameren Missouri’s energy sales;
• legal and administrative proceedings;
• the impact of cyber attacks, which could result in the loss of operational control of energy centers and electric and natural gas transmission and distribution systems and/or the loss of data, such as utility customer data and account information; and
• acts of sabotage, war, terrorism, or other intentionally disruptive acts.

New factors emerge from time to time; it is not possible for management to predict all such factors, nor can it assess the impact of each such factor on the business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained or implied in any forward-looking statement. Given these uncertainties, undue reliance should not be placed on these forward-looking statements. Except to the extent required by the federal securities laws, we undertake no obligation to update or revise publicly any forward-looking statements to reflect new information or future events.