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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-Q
 
Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
for the Quarterly Period Ended March 31, 2021

OR
Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from             to
Commission
File Number
Exact name of registrant as specified in its charter;
State of Incorporation;
Address and Telephone Number
IRS Employer
Identification No.
1-14756Ameren Corporation43-1723446
(Missouri Corporation)
1901 Chouteau Avenue
St. Louis, Missouri 63103
(314) 621-3222
1-2967Union Electric Company43-0559760
(Missouri Corporation)
1901 Chouteau Avenue
St. Louis, Missouri 63103
(314) 621-3222
1-3672Ameren Illinois Company37-0211380
(Illinois Corporation)
10 Executive Drive
Collinsville, Illinois 62234
(618) 343-8150
Securities Registered Pursuant to Section 12(b) of the Act:
Title of each classTrading Symbol(s)Name of each exchange on which registered
Common Stock, $0.01 par value per shareAEENew York Stock Exchange



Indicate by check mark whether the registrants: (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) have been subject to such filing requirements for the past 90 days.
Ameren CorporationYesNo
Union Electric CompanyYesNo
Ameren Illinois CompanyYesNo
Indicate by check mark whether each registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).
Ameren CorporationYesNo
Union Electric CompanyYesNo
Ameren Illinois CompanyYesNo
Indicate by check mark whether each registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
Ameren CorporationLarge accelerated filerAccelerated filerNon-accelerated filer
Smaller reporting companyEmerging growth company
Union Electric CompanyLarge accelerated filerAccelerated filerNon-accelerated filer
Smaller reporting companyEmerging growth company
Ameren Illinois CompanyLarge accelerated filerAccelerated filerNon-accelerated filer
Smaller reporting companyEmerging growth company
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
Ameren Corporation
Union Electric Company
Ameren Illinois Company
Indicate by check mark whether each registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).
Ameren CorporationYesNo
Union Electric CompanyYesNo
Ameren Illinois CompanyYesNo
The number of shares outstanding of each registrant’s classes of common stock as of April 30, 2021, was as follows:
RegistrantTitle of each class of common stockShares outstanding
Ameren CorporationCommon stock, $0.01 par value per share255,552,619 
Union Electric CompanyCommon stock, $5 par value per share, held by Ameren Corporation102,123,834 
Ameren Illinois CompanyCommon stock, no par value, held by Ameren Corporation25,452,373 
______________________________________________________________________________________________________
This combined Form 10-Q is separately filed by Ameren Corporation, Union Electric Company, and Ameren Illinois Company. Each registrant hereto is filing on its own behalf all of the information contained in this quarterly report that relates to such registrant. Each registrant hereto is not filing any information that does not relate to such registrant, and therefore makes no representation as to any such information.



TABLE OF CONTENTS
  Page
Item 1.
Union Electric Company (d/b/a Ameren Missouri)
Ameren Illinois Company (d/b/a Ameren Illinois)
Item 2.
Item 3.
Item 4.
Item 1.
Item 1A.
Item 2.
Item 6.



GLOSSARY OF TERMS AND ABBREVIATIONS
We use the words “our,” “we” or “us” with respect to certain information that relates to Ameren, Ameren Missouri, and Ameren Illinois, collectively. When appropriate, subsidiaries of Ameren Corporation are named specifically as their various business activities are discussed. Refer to the Form 10-K for a complete listing of glossary terms and abbreviations. Only new or significantly changed terms and abbreviations are included below.
Form 10-K – The combined Annual Report on Form 10-K for the year ended December 31, 2020, filed by the Ameren Companies with the SEC.
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, projections, strategies, targets, estimates, 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 within Risk Factors in the Form 10-K and in this report, and elsewhere in this report and in our other filings with the SEC, could cause actual results to differ materially from management expectations suggested in such forward-looking statements:
regulatory, judicial, or legislative actions, and any changes in regulatory policies and ratemaking determinations, that may change regulatory recovery mechanisms, such as those that may result from potential future orders and Ameren Missouri’s electric service and natural gas delivery service regulatory rate reviews filed with the MoPSC in March 2021, the July 2020 appeal filed by Ameren Missouri, Ameren Illinois, and ATXI challenging the refund period related to the May 2020 FERC order determining the allowed base ROE under the MISO tariff, the July 2020 appeal filed by Ameren Missouri, Ameren Illinois, and ATXI challenging the FERC’s rehearing denials in the transmission formula rate revision cases, Ameren Illinois’ request for rehearing of the March 2021 FERC order related to Ameren Illinois’ 2020 transmission formula rate update, and Ameren Illinois’ electric distribution service rate reconciliation request filed with the ICC in April 2021;
the length and severity of the COVID-19 pandemic, and its impacts on our business continuity plans and our results of operations, financial position, and liquidity, including but not limited to changes in customer demand resulting in changes to sales volumes, customers’ payment for our services and their use of deferred payment arrangements, future regulatory or legislative actions that could require suspension of customer disconnections and/or late fees, among other things, for an extended period of time, the health and welfare of our workforce and contractors, supplier disruptions, delays in the completion of construction projects, which could impact our expected capital expenditures and rate base growth, Ameren Missouri’s ability to recover any forgone customer late fee revenues or incremental costs, our ability to meet customer energy-efficiency program goals and earn performance incentives related to those programs, changes in how we operate our business and increased data security risks as a result of the transition to remote working arrangements for a significant portion of our workforce, and our ability to access the capital markets on reasonable terms and when needed;
the effect and duration of Ameren Illinois’ election to participate in performance-based formula ratemaking framework for its electric distribution service, which, unless extended, expires at the end of 2022, and its participation in electric energy-efficiency programs, including the direct relationship between Ameren Illinois’ ROE and the 30-year United States Treasury bond yields;
the effect on Ameren Missouri of any customer rate caps pursuant to Ameren Missouri’s election to use the PISA, including an extension of use beyond 2023, if requested by Ameren Missouri and approved by the MoPSC;
the effects of changes in federal, state, or local laws and other governmental actions, including monetary, fiscal, and energy policies;
the effects of changes in federal, state, or local tax laws, regulations, interpretations, or rates, and challenges to the tax positions taken by the Ameren Companies, if any, as well as resulting effects on customer rates;
the effects on energy prices and demand for our services resulting from technological advances, including advances in customer energy efficiency, electric vehicles, electrification of various industries, energy storage, and private 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 revenues and performance incentives earned under its MEEIA programs;
Ameren Illinois’ ability to achieve the performance standards applicable to its electric distribution business and the FEJA electric customer energy-efficiency goals and the resulting impact on its allowed ROE;
our ability to control costs and make substantial investments in our businesses, including our ability to recover costs, investments, and our allowed ROEs within frameworks established by our regulators, while maintaining affordability of our services for our customers;
1


the cost and availability of fuel, such as low-sulfur coal, natural gas, and enriched uranium used to produce electricity; the cost and availability of purchased power, zero emission credits, renewable energy credits, and natural gas for distribution; and the level and volatility of future market prices for such commodities and credits;
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 nuclear fuel assemblies from the one NRC-licensed supplier of Ameren Missouri’s Callaway Energy Center assemblies;
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;
the effectiveness of our risk management strategies and our use of financial and derivative instruments;
the ability to obtain sufficient insurance, including insurance for Ameren Missouri’s nuclear and coal-fired energy centers, or, in the absence of insurance, the ability to timely recover uninsured losses from our customers;
the impact of cyberattacks on us or our suppliers, which could, among other things, 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 customer, employee, financial, and operating system information;
business and economic conditions, which have been affected by, and will be affected by the length and severity of, the COVID-19 pandemic, including the impact of such conditions on interest rates;
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 actions of credit rating agencies and the effects of such actions, including any impacts on our credit ratings that may result from the economic conditions of the COVID-19 pandemic;
the inability of our counterparties to meet their obligations with respect to contracts, credit agreements, and financial instruments, including as it relates to the construction and acquisition of electric and natural gas utility infrastructure and the ability of counterparties to complete projects which is dependent upon the availability of necessary materials and equipment, including those that are affected by the disruptions in the global supply chain caused by the COVID-19 pandemic;
the impact of weather conditions and other natural phenomena on us and our customers, including the impact of system outages and the level of wind and solar resources;
the construction, installation, performance, and cost recovery of generation, transmission, and distribution assets;
the effects of failures of electric generation, electric and natural gas transmission or distribution, or natural gas storage facilities systems and equipment, which could result in unanticipated liabilities or unplanned outages;
the operation of Ameren Missouri’s Callaway Energy Center, including planned and unplanned outages, such as the current outage that began in December 2020 related to its generator, and the ability to recover costs associated with such outages and the impact of such outages on off-system sales and purchased power, among other things;
Ameren Missouri’s ability to recover 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 impact of current environmental laws and new, more stringent, or changing requirements, including those related to NSR and CO2, other emissions and discharges, cooling water intake structures, CCR, and energy efficiency, that could limit or terminate the operation of certain of Ameren Missouri’s energy centers, increase our operating 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 standards in Missouri and Illinois and with the zero emission standard in Illinois;
Ameren Missouri’s ability to construct and/or acquire wind, solar, and other renewable energy generation facilities, retire energy centers, and implement new or existing customer energy-efficiency programs, including any such construction, acquisition, retirement, or implementation in connection with its Smart Energy Plan, the 2020 IRP, or our emissions reduction goals, and to recover its cost of investment, related return, and, in the case of customer energy-efficiency programs, any lost margins in a timely manner, which is affected by the ability to obtain all necessary regulatory and project approvals, including certificates of convenience and necessity from the MoPSC or any other required approvals for the addition of renewable resources;
the availability of federal production and investment tax credits related to renewable energy and Ameren Missouri’s ability to use such credits; the cost of wind, solar, and other renewable generation and storage technologies; and our ability to obtain timely interconnection agreements with the MISO or other RTOs at an acceptable cost for each facility;
advancements in carbon-free generation and storage technologies, and constructive federal and state energy and economic policies with respect to those technologies;
labor disputes, work force reductions, changes in future wage and employee benefits costs, including those resulting from changes in discount rates, mortality tables, returns on benefit plan assets, and other assumptions;
the impact of negative opinions of us or our utility services that our customers, investors, legislators, or regulators may have or develop, which could result from a variety of factors, including failures in system reliability, failure to implement our investment plans or to protect sensitive customer information, increases in rates, negative media coverage, or concerns about environmental, social, and/or governance practices;
the impact of adopting new accounting guidance;
2


the effects of strategic initiatives, including mergers, acquisitions, and divestitures;
legal and administrative proceedings; and
acts of sabotage, war, terrorism, or other intentionally disruptive acts.
New factors emerge from time to time, and it is not possible for management to predict all of 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.
3


PART I. FINANCIAL INFORMATION
ITEM 1. FINANCIAL STATEMENTS.

AMEREN CORPORATION
CONSOLIDATED STATEMENT OF INCOME AND COMPREHENSIVE INCOME
(Unaudited) (In millions, except per share amounts)
 Three Months Ended March 31,
 20212020
Operating Revenues:
Electric$1,156 $1,120 
Natural gas410 320 
Total operating revenues1,566 1,440 
Operating Expenses:
Fuel65 140 
Purchased power191 134 
Natural gas purchased for resale165 107 
Other operations and maintenance420 438 
Depreciation and amortization281 255 
Taxes other than income taxes128 125 
Total operating expenses1,250 1,199 
Operating Income316 241 
Other Income, Net46 21 
Interest Charges100 93 
Income Before Income Taxes262 169 
Income Taxes27 21 
Net Income 235 148 
Less: Net Income Attributable to Noncontrolling Interests 2 2 
Net Income Attributable to Ameren Common Shareholders$233 $146 
Net Income $235 $148 
Other Comprehensive Income, Net of Taxes
Pension and other postretirement benefit plan activity, net of income taxes of $ and $, respectively
1 1 
Comprehensive Income 236 149 
Less: Comprehensive Income Attributable to Noncontrolling Interests
2 2 
Comprehensive Income Attributable to Ameren Common Shareholders$234 $147 
Earnings per Common Share – Basic$0.92 $0.59 
Earnings per Common Share – Diluted$0.91 $0.59 
Weighted-average Common Shares Outstanding – Basic254.4 246.4 
Weighted-average Common Shares Outstanding – Diluted255.9 248.1 
The accompanying notes are an integral part of these consolidated financial statements.
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AMEREN CORPORATION
CONSOLIDATED BALANCE SHEET
(Unaudited) (In millions, except per share amounts)
March 31, 2021December 31, 2020
ASSETS
Current Assets:
Cash and cash equivalents$6 $139 
Accounts receivable – trade (less allowance for doubtful accounts of $47 and $50, respectively)
464 415 
Unbilled revenue210 269 
Miscellaneous accounts receivable61 65 
Inventories467 521 
Restricted cash134 17 
Current regulatory assets367 109 
Other current assets114 118 
Total current assets1,823 1,653 
Property, Plant, and Equipment, Net27,307 26,807 
Investments and Other Assets:
Nuclear decommissioning trust fund1,010 982 
Goodwill411 411 
Regulatory assets1,249 1,100 
Other assets989 1,077 
Total investments and other assets3,659 3,570 
TOTAL ASSETS$32,789 $32,030 
LIABILITIES AND EQUITY
Current Liabilities:
Current maturities of long-term debt$8 $8 
Short-term debt889 490 
Accounts and wages payable581 958 
Taxes accrued128 82 
Interest accrued84 114 
Current regulatory liabilities225 121 
Other current liabilities392 407 
Total current liabilities2,307 2,180 
Long-term Debt, Net11,527 11,078 
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes and tax credits, net3,253 3,211 
Regulatory liabilities5,230 5,282 
Asset retirement obligations705 696 
Pension and other postretirement benefits38 37 
Other deferred credits and liabilities452 466 
Total deferred credits and other liabilities9,678 9,692 
Commitments and Contingencies (Notes 2, 9, and 10)
Ameren Corporation Shareholders’ Equity:
Common stock, $.01 par value, 400.0 shares authorized – shares outstanding of 255.5 and 253.3, respectively
3 3 
Other paid-in capital, principally premium on common stock6,295 6,179 
Retained earnings2,850 2,757 
Accumulated other comprehensive loss (1)
Total Ameren Corporation shareholders’ equity9,148 8,938 
Noncontrolling Interests129 142 
Total equity9,277 9,080 
TOTAL LIABILITIES AND EQUITY$32,789 $32,030 
The accompanying notes are an integral part of these consolidated financial statements.
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AMEREN CORPORATION
CONSOLIDATED STATEMENT OF CASH FLOWS
(Unaudited) (In millions)
 Three Months Ended March 31,
 20212020
Cash Flows From Operating Activities:
Net income $235 $148 
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization295 263 
Amortization of nuclear fuel 23 
Amortization of debt issuance costs and premium/discounts5 5 
Deferred income taxes and investment tax credits, net26 23 
Allowance for equity funds used during construction(7)(4)
Stock-based compensation costs6 6 
Other8 17 
Changes in assets and liabilities:
Receivables(5)(5)
Inventories54 23 
Accounts and wages payable(252)(221)
Taxes accrued60 47 
Regulatory assets and liabilities(421)(14)
Assets, other(9)(3)
Liabilities, other(34)(18)
Pension and other postretirement benefits4  
Net cash provided by (used in) operating activities(35)290 
Cash Flows From Investing Activities:
Capital expenditures(694)(636)
Wind generation expenditures(193) 
Nuclear fuel expenditures(1)(35)
Purchases of securities – nuclear decommissioning trust fund(152)(96)
Sales and maturities of securities – nuclear decommissioning trust fund150 81 
Other1 2 
Net cash used in investing activities(889)(684)
Cash Flows From Financing Activities:
Dividends on common stock(140)(122)
Dividends paid to noncontrolling interest holders(2)(2)
Short-term debt, net399 175 
Maturities of long-term debt (85)
Issuances of long-term debt450 465 
Issuances of common stock125 13 
Redemptions of Ameren Illinois preferred stock(13) 
Employee payroll taxes related to stock-based compensation(17)(20)
Debt issuance costs(3)(3)
Other(4) 
Net cash provided by financing activities 795 421 
Net change in cash, cash equivalents, and restricted cash(129)27 
Cash, cash equivalents, and restricted cash at beginning of year301 176 
Cash, cash equivalents, and restricted cash at end of period$172 $203 
The accompanying notes are an integral part of these consolidated financial statements.
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AMEREN CORPORATION
CONSOLIDATED STATEMENT OF SHAREHOLDERS’ EQUITY
(Unaudited) (In millions, except per share amounts)
 Three Months Ended March 31,
 20212020
Common Stock$3 $2 
Other Paid-in Capital:
Beginning of year6,179 5,694 
Settlement of forward sale agreement through common shares issuance113  
Shares issued under the DRPlus and 401(k) plan12 13 
Stock-based compensation activity(9)(12)
Other paid-in capital, end of period6,295 5,695 
Retained Earnings:
Beginning of year2,757 2,380 
Net income attributable to Ameren common shareholders233 146 
Dividends on common stock(140)(122)
Retained earnings, end of period2,850 2,404 
Accumulated Other Comprehensive Income (Loss):
Deferred retirement benefit costs, beginning of year(1)(17)
Change in deferred retirement benefit costs1 1 
Deferred retirement benefit costs, end of period (16)
Total accumulated other comprehensive loss, end of period (16)
Total Ameren Corporation Shareholders’ Equity$9,148 $8,085 
Noncontrolling Interests:
Beginning of year142 142 
Net income attributable to noncontrolling interest holders2 2 
Dividends paid to noncontrolling interest holders(2)(2)
Redemptions of Ameren Illinois preferred stock(13) 
Noncontrolling interests, end of period129 142 
Total Equity$9,277 $8,227 
Common stock shares outstanding at beginning of year253.3 246.2 
Shares issued under forward sale agreement1.6  
Shares issued under the DRPlus and 401(k) plan0.1 0.2 
Shares issued for stock-based compensation0.5 0.5 
Common stock shares outstanding at end of period255.5 246.9 
Dividends per common share$0.550 $0.495 
The accompanying notes are an integral part of these consolidated financial statements.
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UNION ELECTRIC COMPANY (d/b/a AMEREN MISSOURI)
STATEMENT OF INCOME (LOSS)
(Unaudited) (In millions)
 Three Months Ended March 31,
 20212020
Operating Revenues:
Electric$641 $631 
Natural gas63 49 
Total operating revenues704 680 
Operating Expenses:
Fuel65 140 
Purchased power88 39 
Natural gas purchased for resale31 18 
Other operations and maintenance225 239 
Depreciation and amortization156 139 
Taxes other than income taxes77 79 
Total operating expenses642 654 
Operating Income62 26 
Other Income, Net23 4 
Interest Charges39 40 
Income (Loss) Before Income Taxes46 (10)
Income Tax Benefit(2)(1)
Net Income (Loss)48 (9)
Preferred Stock Dividends1 1 
Net Income (Loss) Available to Common Shareholder$47 $(10)
The accompanying notes as they relate to Ameren Missouri are an integral part of these financial statements.
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UNION ELECTRIC COMPANY (d/b/a AMEREN MISSOURI)
BALANCE SHEET
(Unaudited) (In millions, except per share amounts)
March 31, 2021December 31, 2020
ASSETS
Current Assets:
Cash and cash equivalents$1 $136 
Advances to money pool 139 
Accounts receivable – trade (less allowance for doubtful accounts of $15 and $16, respectively)
156 166 
Accounts receivable – affiliates69 57 
Unbilled revenue109 133 
Miscellaneous accounts receivable43 36 
Inventories362 386 
Current regulatory assets