Item 1. BUSINESS

GENERAL

Ameren, formed in 1997 and headquartered in St. Louis, Missouri, is a public utility holding company whose primary assets are its equity interests in its subsidiaries. Ameren’s subsidiaries are separate, independent legal entities with separate businesses, assets, and liabilities. Dividends on Ameren’s common stock and the payment of expenses by Ameren depend on distributions made to it by its subsidiaries.

Below is a summary description of Ameren’s principal subsidiaries – Ameren Missouri, Ameren Illinois, and ATXI. Ameren also has other subsidiaries that conduct other activities, such as providing shared services. A more detailed description can be found in Note 1 – Summary of Significant Accounting Policies under Part II, Item 8, of this report.

•	Ameren Missouri operates a rate-regulated electric generation, transmission, and distribution business and a rate-regulated natural gas distribution business in Missouri.

•	Ameren Illinois operates rate-regulated electric transmission, electric distribution, and natural gas distribution businesses in Illinois.

•	ATXI operates a FERC rate-regulated electric transmission business in the MISO.

The following table presents our employees by function at December 31, 2019:

Ameren Missouri:
Electric and natural gas transmission and distribution	1,716
Generation	1,721
Other support services	635
Total Ameren Missouri	4,072
Ameren Illinois:
Electric and natural gas transmission and distribution	2,856
Other support services	620
Total Ameren Illinois	3,476
Ameren Services – support services	1,775
Total Ameren	9,323

Labor unions at Ameren’s subsidiaries consist of the International Brotherhood of Electrical Workers, the International Union of Operating Engineers, the Laborer’s International Union of North America, the United Association of Plumbers and Pipefitters, and the United Government Security Officers of America. At December 31, 2019, these labor unions collectively represented about 50% of Ameren’s total employees. They represented 60% and 56% of the employees at Ameren Missouri and Ameren Illinois, respectively. The Ameren Missouri collective bargaining unit contracts expire in 2021 and 2022, which cover 3% and 97% of represented employees, respectively. The Ameren Illinois collective bargaining unit contracts expire in 2020, 2021, 2022, and 2023, which cover 1%, 92%, 1%, and 6% of represented employees, respectively.

For additional information about the development of our businesses, our business operations, and factors affecting our results of operations, financial position, and liquidity, see Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, of this report and Note 1 – Summary of Significant Accounting Policies and Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

BUSINESS SEGMENTS

Ameren has four segments: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. The Ameren Missouri segment includes all of the operations of Ameren Missouri. Ameren Illinois Electric Distribution consists of the electric distribution business of Ameren Illinois. Ameren Illinois Natural Gas consists of the natural gas business of Ameren Illinois. Ameren Transmission primarily consists of the aggregated electric transmission businesses of Ameren Illinois and ATXI.

Ameren Missouri has one segment. Ameren Illinois has three segments: Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission.

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

(a)	The Ameren Transmission segment also includes allocated Ameren (parent) interest charges, Ameren Transmission Company, LLC, ATX East, LLC, and ATX Southwest, LLC.

RATES AND REGULATION

Rates

The rates that Ameren Missouri, Ameren Illinois, and ATXI are allowed to charge for their utility services significantly influence the results of operations, financial position, and liquidity of these companies and Ameren. The electric and natural gas utility industry is highly regulated. The utility rates charged to customers are determined by governmental entities, including the MoPSC, the ICC, and the FERC. Decisions by these entities are influenced by many factors, including the cost of providing service, the prudency of expenditures, the quality of service, regulatory staff knowledge and experience, customer intervention, and economic conditions, as well as social and political views. Decisions made by these governmental entities regarding rates are largely outside of our control. These decisions, as well as the regulatory lag involved in the process of getting new rates approved, could have a material adverse effect on the results of operations, financial position, and liquidity of the Ameren Companies. The extent of the regulatory lag varies for each of Ameren’s electric and natural gas jurisdictions, with the Ameren Transmission and Ameren Illinois Electric Distribution businesses experiencing the least amount of regulatory lag. Depending on the jurisdiction, the effects of regulatory lag are mitigated by various means, including annual revenue requirement reconciliations, the decoupling of revenues from sales volumes to ensure revenues approved in a regulatory rate review are not affected by changes in sales volumes, the recovery of certain capital investments between traditional regulatory rate reviews, the level and timing of expenditures, the use of a future test year, and the use of trackers and riders.

The MoPSC regulates rates and other matters for Ameren Missouri. The ICC regulates rates and other matters for Ameren Illinois. The MoPSC and the ICC regulate non-rate utility matters for ATXI. ATXI does not have retail distribution customers; therefore, the MoPSC and the ICC do not have authority to regulate ATXI’s rates. The FERC regulates Ameren Missouri’s, Ameren Illinois’, and ATXI’s cost-based rates for the wholesale transmission and distribution of energy in interstate commerce and various other matters discussed below under General Regulatory Matters.

For additional information on Ameren Missouri, Ameren Illinois, and ATXI rate matters, see Results of Operations and Outlook in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, Quantitative and Qualitative Disclosures About Market Risk under Part II, Item 7A, and Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

The following table summarizes the key terms of the rate orders in effect for customer billings for each of Ameren’s rate-regulated utilities as of January 1, 2020:

	Rate Regulator	Effective Rate Order Issued In	Allowed ROE	Percent of Common Equity	Rate Base (in billions)	Portion of Ameren’s 2019 Operating Revenues**(a)**
Ameren Missouri
Electric service(b)	MoPSC	March 2017(c)	9.2% – 9.7%(c)	(c)	(c)	52%
Natural gas delivery service	MoPSC	August 2019(d)	9.4% – 9.95%(d)	52.0%	(d)	2%
Ameren Illinois
Electric distribution delivery service(e)	ICC	December 2019	8.91%	50.0%	$3.2	25%
Natural gas delivery service(f)	ICC	November 2018	9.87%	50.0%	$1.6	14%
Electric transmission service(g)	FERC	(g)	10.38%	51.3%	$2.1	4%
ATXI
Electric transmission service(g)	FERC	(g)	10.38%	59.3%	$1.4	3%

(a)	Includes pass-through costs recovered from customers, such as purchased power for electric distribution delivery service and natural gas purchased for resale for natural gas delivery service, and intercompany eliminations.

(b)

Ameren Missouri’s electric generation, transmission, and delivery service rates are bundled together and charged to retail customers under a combined electric service rate. Ameren Missouri has a pending electric service regulatory rate review it filed with the MoPSC in July 2019. For additional information regarding this regulatory rate review, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

(c)	This rate order specified that an implicit ROE was within a range of 9.2% to 9.7%. This rate order did not specify a percent of common equity or rate base. The ROE used for allowance for equity funds used during construction is 9.53%.

(d)	This rate order specified that an implicit ROE was within a range of 9.4% to 9.95%. This rate order did not specify rate base.

(e)

Ameren Illinois electric distribution delivery service rates are updated annually and become effective each January. This rate order was based on 2018 actual costs, expected net plant additions for 2019, and the annual average of the monthly yields during 2018 of the 30-year United States Treasury bonds plus 580 basis points. Ameren Illinois’ 2020 electric distribution delivery service revenues will be based on its 2020 actual recoverable costs, rate base, common equity percentage, and an allowed ROE, as calculated under the IEIMA’s performance-based formula ratemaking framework.

(f)	This rate order was based on a 2019 future test year. Ameren Illinois has a pending natural gas delivery service regulatory rate review it filed with the ICC in February 2020. For additional information regarding this regulatory rate review, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

(g)

Transmission rates are updated annually and become effective each January. They are determined by a company-specific, forward-looking formula ratemaking framework based on each year’s forecasted information. The 10.38% return, which includes a 50 basis points incentive adder for participation in an RTO, is based on the FERC’s November 2019 order. For additional information regarding this order and related requests for rehearing, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report. The ROE applicable to investments in ATXI’s Mark Twain project includes an additional 50 basis point incentive adder related to the unique nature of risks involved in completing the project.

General Regulatory Matters

Ameren Missouri, Ameren Illinois, and ATXI must receive FERC approval to enter into various transactions, such as issuing short-term debt securities and conducting certain acquisitions, mergers, and consolidations involving electric utility holding companies. In addition, Ameren Missouri, Ameren Illinois, and ATXI must receive authorization from the applicable state public utility regulatory agency to issue stock and long-term debt securities and to conduct mergers, affiliate transactions, and various other activities.

Ameren Missouri, Ameren Illinois, and ATXI are also subject to mandatory reliability standards, including cybersecurity standards adopted by the FERC, to ensure the reliability of the bulk electric power system. These standards are developed and enforced by the NERC, pursuant to authority delegated to it by the FERC. Ameren Missouri, Ameren Illinois, and ATXI are members of the SERC. The SERC is one of eight regional entities representing all or portions of 16 central and southeastern states under authority from the NERC for the purpose of implementing and enforcing reliability standards approved by the FERC. The regional entities of the NERC work to safeguard the reliability of the bulk power systems throughout North America. If any of Ameren Missouri, Ameren Illinois, or ATXI is found not to be in compliance with these mandatory reliability standards, it could incur substantial monetary penalties and other sanctions.

Under the Public Utility Holding Company Act of 2005, the FERC and the state public utility regulatory agencies in each state Ameren and its subsidiaries operate in may access books and records of Ameren and its subsidiaries that are found to be relevant to costs incurred by Ameren’s rate-regulated subsidiaries that may affect jurisdictional rates. The act also permits the MoPSC and the ICC to request that the FERC review cost allocations by Ameren Services to other Ameren companies.

Operation of Ameren Missouri’s Callaway Energy Center is subject to regulation by the NRC. The license for the Callaway Energy Center expires in 2044. Ameren Missouri’s hydroelectric Osage Energy Center and pumped-storage hydroelectric Taum Sauk Energy Center, as licensed projects under the Federal Power Act, are subject to FERC regulations affecting, among other aspects, the general operation and maintenance of the projects. The licenses for the Osage Energy Center and the Taum Sauk Energy Center expire in 2047 and 2044, respectively. Ameren Missouri’s Keokuk Energy Center and its dam in the Mississippi River between Hamilton, Illinois, and Keokuk, Iowa, are operated under authority granted by an Act of Congress in 1905.

For additional information on regulatory matters, see Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

Environmental Matters

Certain of our operations are subject to federal, state, and local environmental laws, including statutes and regulations, relating to the protection of the safety and health of our personnel, the public, and the environment. These laws include requirements relating to identification, generation, storage, handling, transportation, disposal, recordkeeping, labeling, reporting, and emergency response in connection with hazardous and toxic materials; safety and health standards; and environmental protection requirements, including standards and limitations relating to the discharge of air and water pollutants, water intake, and the management of waste and byproduct materials. These environmental regulations could also affect the availability of, the cost of, and the demand for electricity and natural gas sold to Ameren Missouri’s and Ameren Illinois’ customers as well as the demand for off-system sales. Federal, state, and local authorities continually revise these regulations, which adds uncertainty to our planning process and to the ultimate implementation of these or other new or revised regulations. Failure to comply with these laws could have a material adverse effect on us. We could be subject to criminal or civil penalties by regulatory agencies, or we could be ordered by the courts to pay private parties. Except as indicated in this report, we believe that we are in material compliance with existing laws that currently apply to our operations.

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

TRANSMISSION

Ameren owns an integrated transmission system that is composed of the transmission assets of Ameren Missouri, Ameren Illinois, and ATXI. Ameren also operates two MISO balancing authority areas: AMMO and AMIL. The AMMO balancing authority area includes the load and energy centers of Ameren Missouri, and had a peak demand of 7,363 megawatts in 2019. The AMIL balancing authority area includes the load of Ameren Illinois, and had a peak demand of 8,735 megawatts in 2019. The Ameren transmission system directly connects with 15 other balancing authority areas for the exchange of electric energy.

Ameren Missouri, Ameren Illinois, and ATXI are transmission-owning members of the MISO. Ameren Missouri is authorized by the MoPSC to participate in the MISO through May 2024. Ameren Missouri is periodically required to make a filing with the MoPSC regarding its continued participation in the MISO. The next filing is due in 2023.

SUPPLY OF ELECTRIC POWER

Ameren Missouri

Ameren Missouri’s electric supply is primarily generated from its energy centers. Factors that could cause Ameren Missouri to purchase power include, among other things, energy center outages, the fulfillment of renewable energy requirements, extreme weather conditions, the availability of power at a cost lower than its generation cost, and the lack of sufficient owned generation. Additionally, Ameren Missouri may need to fulfill purchased power needs from another source if a supplier is unable to meet its power supply obligations.

Ameren Missouri files a nonbinding 20-year integrated resource plan with the MoPSC every three years. The most recent integrated resource plan, filed in September 2017, includes Ameren Missouri’s preferred approach for meeting customers’ projected long-term energy needs in a cost-effective manner while maintaining system reliability. The plan targets cleaner and more diverse sources of energy generation, including solar, wind, natural gas, hydroelectric, and nuclear power. It also includes expanding renewable energy generation by adding 700 megawatts of wind generation by 2020 in Missouri, adding 100 megawatts of solar generation by 2027, expanding customer energy-efficiency programs, adding cost-effective demand response programs, and retiring coal-fired energy centers as they reach the end of their useful lives. Ameren Missouri may be adversely affected if the MoPSC does not allow recovery of the remaining investment, if any, 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. Ameren Missouri expects to file its next integrated resource plan in September 2020.

Ameren Missouri continues to evaluate its longer-term needs for new generating capacity. The need for investment in new sources of energy is dependent on several key factors, including continuation of and customer participation in energy-efficiency programs, the amount of distributed generation from customers, load growth, technological advancements, costs of generation alternatives, environmental regulation of coal-fired power plants, and state renewable energy requirements, which could lead to the retirement of current baseload assets before the end of their useful lives or alterations in the way those assets operate, which could result in increased capital expenditures and/or increased operations and maintenance expenses. Because of the significant time required to plan, acquire permits for, and build a baseload energy center, Ameren Missouri continues to study alternatives and to take steps to preserve options to meet future demand. Steps include

evaluating the potential for further diversification of Ameren Missouri’s generation portfolio through renewable energy generation, including wind and solar generation, additional customer energy-efficiency and demand response programs, distributed energy resources, and energy storage.

Ameren Illinois

In Illinois, while electric transmission and distribution service rates are regulated, power supply prices are not. Although electric customers are allowed to purchase power from an alternative retail electric supplier, Ameren Illinois is required to be the provider of last resort for its electric distribution customers. In 2019, 2018, and 2017, Ameren Illinois procured power on behalf of its customers for 22%, 23%, and 23%, respectively, of its total kilowatthour sales. Power purchased by Ameren Illinois for its electric distribution customers who do not elect to purchase their power from an alternative retail electric supplier comes either through procurement processes conducted by the IPA or through markets operated by the MISO. The IPA administers an RFP process through which Ameren Illinois procures its expected supply. The power and related procurement costs incurred by Ameren Illinois are passed directly to its electric distribution customers through a cost recovery mechanism. The costs are reflected in Ameren Illinois Electric Distribution’s results of operations, but do not affect Ameren Illinois Electric Distribution’s earnings, because these costs are offset by corresponding revenues. Ameren Illinois charges transmission and distribution service rates to electric distribution customers who purchase electricity from alternative retail electric suppliers, which does affect Ameren Illinois Electric Distribution’s earnings.

Illinois law requires Ameren Illinois to offer rebates for certain net metering customers. The cost of the rebates are deferred as a regulatory asset, which earn a return at the applicable WACC. Customers that receive these rebates are allowed to net their supply service charges, but not their distribution service charges. Beginning in 2017, the FEJA decoupled the electric distribution revenues established in a regulatory rate review from the actual sales volumes, which ensures that Ameren Illinois’ electric distribution revenues are not affected by any changes in sales volumes.

POWER GENERATION

Ameren Missouri owns energy centers that rely on a diverse fuel portfolio, including coal, nuclear, and natural gas, as well as renewable sources of generation, which include hydroelectric, methane gas, and solar. All of Ameren Missouri’s coal-fired energy centers were constructed prior to 1978. The Callaway nuclear energy center began operation in 1984 and is licensed to operate until 2044. As of December 31, 2019, Ameren Missouri’s coal-fired energy centers represented 12% and 26% of Ameren’s and Ameren Missouri’s rate base, respectively. See Item 2 – Properties under Part I of this report for information regarding Ameren Missouri’s energy centers.

Coal

Ameren Missouri has an ongoing need for coal as fuel for generation, and pursues a price-hedging strategy consistent with this requirement. Ameren Missouri has agreements in place to purchase and transport coal to its energy centers. As of December 31, 2019, Ameren Missouri had price-hedged 100% of its expected coal supply and 100% of its coal transportation requirements for generation in 2020. Ameren Missouri has additional coal supply under contract through 2025. The Powder River Basin coal transport agreements that Ameren Missouri has with Union Pacific Railroad and Burlington Northern Santa Fe Railway are currently set to expire at the end of 2024. Ameren Missouri burned approximately 14.3 million tons of coal in 2019.

About 97% of Ameren Missouri’s coal is purchased from the Powder River Basin in Wyoming, which has a limited number of suppliers. The remaining coal is typically purchased from the Illinois Basin. Targeted coal inventory levels may be adjusted because of generation levels or uncertainties of supply due to potential work stoppages, delays in coal deliveries, equipment breakdowns, and other factors. Deliveries from the Powder River Basin have occasionally been restricted because of rail congestion and maintenance, derailments, weather, and supplier financial hardship. Coal suppliers in the Power River Basin are experiencing financial hardship because of a decrease in demand resulting from increased natural gas and renewable energy generation, and the impact of environmental regulations, as well as concerns related to coal-fired generation. These financial hardships have resulted in bankruptcy filings by certain coal suppliers in recent years. As of December 31, 2019, coal inventories for Ameren Missouri were near targeted levels. Disruptions in coal deliveries could cause Ameren Missouri to pursue a strategy that could include reducing wholesale sales of power during low-margin periods, buying higher-cost fuels to generate required electricity, and purchasing power from other sources.

Nuclear

The production of nuclear fuel involves the mining and milling of uranium ore to produce uranium concentrates, the conversion of uranium concentrates to uranium hexafluoride gas, the enrichment of that gas, the conversion of the enriched uranium hexafluoride gas into uranium dioxide fuel pellets, and the fabrication into fuel assemblies. Ameren Missouri has entered into uranium, uranium conversion, uranium enrichment, and fabrication contracts to procure the fuel supply for its Callaway Energy Center.

The Callaway Energy Center requires refueling at 18-month intervals. The last refueling was completed in May 2019. The next refueling is scheduled for the fall of 2020. Ameren Missouri has inventories, supply contracts, and fuel fabrication service contracts sufficient to meet all of its uranium (concentrate and hexafluoride), conversion, and enrichment requirements at least through the 2023 refueling.

RENEWABLE ENERGY AND ZERO EMISSION STANDARDS

Missouri and Illinois laws require electric utilities to include renewable energy resources in their portfolios. Ameren Missouri and Ameren Illinois satisfied their renewable energy portfolio requirements in 2019.

In Missouri, utilities were required to purchase or generate electricity equal to at least 10% of native load sales from renewable energy sources in 2019, and will be required to purchase or generate at that same threshold in 2020. The requirement will increase to at least 15% in 2021, subject to an average 1% annual increase on customer rates over any 10-year period. At least 2% of the annual renewable energy requirement must be derived from solar energy. Ameren Missouri expects to satisfy the nonsolar requirement in 2020 with its Keokuk and Maryland Heights energy centers, a 102-megawatt power purchase agreement with a wind farm operator, and an estimated purchase of approximately $1 million of renewable energy credits in the market. The Keokuk Energy Center generates electricity using a hydroelectric dam located on the Mississippi River. The Maryland Heights Energy Center generates electricity by burning methane gas collected from a landfill. Ameren Missouri is meeting the solar energy requirement by purchasing solar-generated renewable energy credits from customer-installed systems and by generating solar energy at its O’Fallon, Lambert, and BJC energy centers and its headquarters building. In May 2019, Ameren Missouri entered into a build-transfer agreement to acquire, after construction, an up-to 300-megawatt wind generation facility. In 2018, Ameren Missouri entered into a build-transfer agreement to acquire, after construction, an up-to 400-megawatt wind generation facility. Both facilities are expected to be completed by the end of 2020 and would support Ameren Missouri’s compliance with the Missouri renewable energy standard. For additional information on these agreements, see Note 2 – Rate and Regulatory Matters under Part II, Item 8 of this report.

Effective June 2017, the FEJA requires Ameren Illinois to collect funds from all electric distribution customers to fund IPA procurement events for renewable energy credits. In accordance with Illinois law, the amount collected from customers by Ameren Illinois is capped at $1.81 per megawatthour. The IPA establishes its long-term renewable resources procurement plans in a filing made every two years. The IPA’s initial long-term renewable resources procurement plan was approved by the ICC in 2018. The IPA’s plan set forth guidelines by which the IPA should procure 15-year contracts for wind renewable energy credits and solar renewable energy credits. As a result, Ameren Illinois is required to purchase 1.2 million wind renewable energy credits per year and 1.2 million solar renewable energy credits per year, through IPA procurement events, which represented approximately 7% of Ameren Illinois’ electric distribution sales in 2019. The IPA has completed several procurement events, resulting in contractual commitments of 0.9 million wind renewable energy credits per year and 1.1 million solar renewable energy credits per year for Ameren Illinois. Ameren Illinois will execute additional renewable energy credit contracts in 2020 and 2021, through IPA procurement events, in order to fulfill its remaining obligations. In February 2020, the ICC approved the IPA’s second long-term renewable resources procurement plan. Under the second plan, based on forecasted customer collections to fund renewable energy credit contracts, the IPA does not anticipate procuring additional contracts. However, if customer funds collected exceed the cost of procured contracts, the IPA may procure additional contracts. Funds collected but not used to procure renewable energy credits will be refunded to customers pursuant to a reconciliation proceeding that would be initiated after August 2021.

The FEJA also required Ameren Illinois to enter into contracts for zero emission credits in an amount equal to approximately 16% of the actual amount of electricity delivered to retail customers during calendar year 2014, pursuant to Illinois’ zero emission standard. This one-time zero emission credit procurement by the IPA, approval by the ICC, and execution of zero emission credit contracts, which expire in 2026, were completed in 2018. Both renewable energy credits and zero emission credits have cost recovery mechanisms, which allow Ameren Illinois to collect from, or refund to, customers differences between actual costs incurred from the resulting contracts and the amounts collected from customers.

CUSTOMER ENERGY-EFFICIENCY PROGRAMS

Ameren Missouri and Ameren Illinois have implemented energy-efficiency programs to educate and to help their customers become more efficient energy consumers. In Missouri, the Missouri Energy Efficiency Investment Act established a rate-adjustment mechanism that, among other things, allows electric utilities to recover costs with respect to MoPSC-approved customer energy-efficiency programs. The law requires the MoPSC to ensure that a utility’s financial incentives are aligned to help customers use energy more efficiently, to provide timely cost recovery, and to provide earnings opportunities associated with cost-effective energy-efficiency programs. Missouri does not have a law mandating energy-efficiency programs.

In December 2018, the MoPSC issued an order approving Ameren Missouri’s MEEIA 2019 plan. The plan includes a portfolio of customer energy-efficiency programs through December 2021 and low-income customer energy-efficiency programs through December 2024, along with a rate-adjustment mechanism. Ameren Missouri intends to invest $226 million over the life of the plan, including $65 million per year through 2021. In addition, the plan includes a performance incentive that provides Ameren Missouri an opportunity to earn additional revenues by achieving certain customer energy-efficiency goals. If the target goals are achieved for 2019, 2020, and 2021, additional

revenues of $7 million, $10 million, and $13 million would be recognized in late 2020, 2021, and 2022, respectively. Incremental additional revenues of up to $1 million, $3 million, and $3 million may be earned for 2019, 2020, and 2021, respectively, and would be recognized in the respective following year, if Ameren Missouri exceeds its targeted energy savings goals. Through 2019, Ameren Missouri has invested $52 million in MEEIA 2019 customer energy-efficiency programs.

The MEEIA 2019 plan includes the continued use of the MEEIA rider. The MEEIA rider allows Ameren Missouri to collect from, or refund to, customers any difference between actual program costs, lost electric margins, and any performance incentive and the amounts collected from customers, without a traditional regulatory rate review until lower volumes resulting from the MEEIA programs are reflected in base rates. Customer rates, based upon both forecasted program costs and lost electric margins and collected via the MEEIA rider, are reconciled annually to actual results.

State law requires Ameren Illinois to offer customer energy-efficiency programs, and imposes electric energy-efficiency savings goals and a maximum amount of investment in electric energy-efficiency programs through 2030, which is approximately $100 million annually. In September 2017, the ICC issued an order approving Ameren Illinois’ electric and natural gas energy-efficiency plans, as well as regulatory recovery mechanisms. The order authorized electric and natural gas energy-efficiency program expenditures of $394 million and $62 million, respectively, for the 2018 through 2021 period. Additionally, as part of its IEIMA capital project investments, Ameren Illinois has invested $420 million in smart-grid infrastructure since 2012, including smart meters that enable customers to improve their energy efficiency, and expects to spend another $20 million by 2021.

The FEJA allows Ameren Illinois to earn a return on its electric energy-efficiency program investments made since June 2017. Ameren Illinois’ electric energy-efficiency investments are deferred as a regulatory asset and earn a return at the applicable WACC, with the ROE based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points. The allowed ROE on electric energy-efficiency investments can be increased or decreased by up to 200 basis points, depending on the achievement of annual energy savings goals. Pursuant to the FEJA, Ameren Illinois plans to invest up to approximately $100 million per year in electric energy-efficiency programs through 2024, and will earn a return on those investments. While the ICC has approved a plan consistent with this spending level through 2021, the ICC has the ability to reduce the amount of electric energy-efficiency savings goals in future plan program years if there are insufficient cost-effective programs available, which could reduce the investments in electric energy-efficiency programs. The electric energy-efficiency program investments and the return on those investments are collected from customers through a rider and are not included in the electric distribution formula ratemaking framework. Ameren Illinois' natural gas energy efficiency program costs are recovered as they are incurred through a regulatory recovery mechanism.

NATURAL GAS SUPPLY FOR DISTRIBUTION

Ameren Missouri and Ameren Illinois are responsible for the purchase and delivery of natural gas to their customers. Ameren Missouri and Ameren Illinois each develop and manage a portfolio of natural gas supply resources. These resources include firm natural gas supply agreements with producers, firm interstate and intrastate transportation capacity, firm no-notice storage capacity leased from interstate pipelines, and on-system storage facilities to maintain natural gas deliveries to customers throughout the year and especially during peak demand periods. Ameren Missouri and Ameren Illinois primarily use Panhandle Eastern Pipe Line Company, Trunkline Gas Company, Natural Gas Pipeline Company of America, Mississippi River Transmission Corporation, Northern Border Pipeline Company, and Texas Eastern Transmission Corporation interstate pipeline systems to transport natural gas to their systems. In addition to transactions requiring physical delivery, certain financial instruments, including those entered into in the New York Mercantile Exchange futures market and in the over-the-counter financial markets, are used to hedge the price paid for natural gas. Natural gas supply costs are passed on to customers of Ameren Missouri and Ameren Illinois under PGA clauses, subject to prudence reviews by the MoPSC and the ICC. As of December 31, 2019, Ameren Missouri and Ameren Illinois had price-hedged 65% and 79%, respectively, of their expected 2020 natural gas supply requirements.

For additional information on our fuel, purchased power, and natural gas for distribution supply, see Results of Operations and Liquidity and Capital Resources in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, of this report and Commodity Price Risk under Part II, Item 7A, of this report. Also see Note 1 – Summary of Significant Accounting Policies, Note 7 – Derivative Financial Instruments, Note 13 – Related-party Transactions, Note 14 – Commitments and Contingencies, and Note 15 – Supplemental Information under Part II, Item 8 of this report.

INDUSTRY ISSUES

We are facing issues common to the electric and natural gas utility industry. These issues include:

•	the potential for changes in laws, regulations, enforcement efforts, and policies at the state and federal levels;

•	corporate tax law changes, as well as additional interpretations, regulations, amendments, or technical corrections that affect the amount and timing of income tax payments, reduce or limit the ability to claim certain deductions and use carryforward tax benefits, or result in rate base reductions;

•	cybersecurity risks, including the loss of operational control of energy centers and electric and natural gas transmission and distribution systems and/or the theft or inappropriate release of certain types of information, including sensitive customer, employee, financial, and operating system information;

•	political, regulatory, and customer resistance to higher rates;

•	the potential for more intense competition in generation, supply, and distribution, including new technologies and their declining costs;

•	the impact and effectiveness of vegetation management programs;

•	net metering rules and other changes in existing regulatory frameworks and recovery mechanisms to address the allocation of costs to customers who own generation resources that enable them both to sell power to us and to purchase power from us through the use of our transmission and distribution assets;

•	legislation or programs to encourage or mandate energy efficiency, energy conservation, and renewable sources of power, and the lack of consensus as to how those programs should be paid for;

•	pressure on customer growth and usage in light of economic conditions, distributed generation, energy storage, technological advances, and energy-efficiency or conservation initiatives;

•	changes in the structure of the industry as a result of changes in federal and state laws, including the formation and growth of independent transmission entities;

•	changes in the allowed ROE on FERC-regulated electric transmission assets;

•	the availability of fuel and fluctuations in fuel prices;

•	the availability of materials and equipment, and the potential disruptions in supply chains resulting from the international public health emergency associated with the novel coronavirus (COVID-19);

•	the availability of a skilled work force, including retaining the specialized skills of those who are nearing retirement;

•	regulatory lag;

•	the influence of macroeconomic factors on yields of United States Treasury securities and on the allowed ROE provided by regulators;

•	higher levels of infrastructure and technology investments and adjustments to customer rates associated with the TCJA that are expected to result in negative or decreased free cash flow, which is defined as cash flows from operating activities less cash flows from investing activities and dividends paid;

•	the demand for access to renewable energy generation at rates acceptable to customers;

•	public concerns about the siting of new facilities, and challenges that members of the public can assert against applications for governmental permits and other approvals required to site and build new facilities that can result in significant cost increases, delays and denial of the permits and approvals by the regulators;

•	complex new and proposed environmental laws including statutes, regulations, and requirements, such as air and water quality standards, mercury emissions standards, CCR management requirements, and potential CO2 limitations, which may reduce the frequency at which electric generating units are dispatched based upon their CO2 emissions;

•	public concerns about the potential environmental impacts from the combustion of fossil fuels and the use of natural gas;

•	certain investors’ concerns about investing in utility companies that have coal-fired generation assets and increasing scrutiny of environmental, social, and governance practices;

•	aging infrastructure and the need to construct new power generation, transmission, and distribution facilities, which have long time frames for completion, with limited long-term ability to predict power and commodity prices and regulatory requirements;

•	public concerns about nuclear generation, decommissioning, and the disposal of nuclear waste; and

•	consolidation of electric and natural gas utility companies.

We are monitoring all these issues. Except as otherwise noted in this report, we are unable to predict what impact, if any, these issues will have on our results of operations, financial position, or liquidity. For additional information, see Risk Factors under Part I, Item 1A, Outlook in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

OPERATING STATISTICS

The following tables present key electric and natural gas operating statistics for Ameren for the past three years:

Electric Operating Statistics – Year Ended December 31,	2019				2018				2017
Electric Sales – kilowatthours (in millions):
Ameren Missouri:
Residential	13,532				14,320				12,653
Commercial	14,269				14,791				14,384
Industrial	4,242				4,499				4,469
Street lighting and public authority	99				108				117
Ameren Missouri retail load subtotal	32,142				33,718				31,623
Off-system	5,477				10,036				10,640
Ameren Missouri total	37,619				43,754				42,263
Ameren Illinois Electric Distribution(a):
Residential	11,675				12,099				10,985
Commercial	12,341				12,717				12,382
Industrial	11,587				11,673				11,436
Street lighting and public authority	491				513				515
Ameren Illinois Electric Distribution total	36,094				37,002				35,318
Eliminate affiliate sales	(84		)		(288		)		(440		)
Ameren total	73,629				80,468				77,141
Electric Operating Revenues (in millions):
Ameren Missouri:
Residential	$	1,403			$	1,560			$	1,417
Commercial	1,157				1,271				1,208
Industrial	278				312				305
Other, including street lighting and public authority	127				30			(b)	111
Ameren Missouri retail load subtotal	$	2,965			$	3,173			$	3,041
Off-system	144				278				370
Ameren Missouri total	$	3,109			$	3,451			$	3,411
Ameren Illinois Electric Distribution:
Residential	$	848			$	867			$	870
Commercial	497				511				527
Industrial	127				130				113
Other, including street lighting and public authority	32				39				58
Ameren Illinois Electric Distribution total	$	1,504			$	1,547			$	1,568
Ameren Transmission:
Ameren Illinois Transmission(c)	$	288			$	267			$	258
ATXI	176				166				168
Ameren Transmission total	$	464			$	433			$	426
Other and intersegment eliminations	(96		)		(92		)		(98		)
Ameren total	$	4,981			$	5,339			$	5,307

(a)	Sales for which power was supplied by Ameren Illinois as well as alternative retail electric suppliers. In 2019, 2018, and 2017, Ameren Illinois procured power on behalf of its customers for 22%, 23%, and 23%, respectively, of its total kilowatthour sales.

(b)	Includes $60 million for the year ended December 31, 2018, for the reduction to revenue for the excess amounts collected in rates related to the TCJA from January 1, 2018, through July 31, 2018. See Note 2 – Rate and Regulatory Matters for additional information.

(c)	Includes $62 million, $53 million, and $42 million in 2019, 2018, and 2017, respectively, of electric operating revenues from transmission services provided to Ameren Illinois Electric Distribution.

Electric Operating Statistics – Year Ended December 31,	2019				2018				2017
Ameren Missouri fuel costs (cents per kilowatthour generated)(a)		1.38	¢			1.59	¢			1.75	¢
Source of Ameren Missouri energy supply:
Coal	63.4		%		67.8		%		70.9		%
Nuclear	23.3				23.7				19.0
Hydroelectric	5.0				2.5				3.4
Natural gas	0.5				1.0				0.7
Methane gas and solar	0.2				0.1				0.1
Purchased – wind	0.7				0.6				0.7
Purchased power	6.9				4.3				5.2
Ameren Missouri total	100.0		%		100.0		%		100.0		%

(a) Ameren Missouri fuel costs exclude $5 million, $44 million, and $(35) million in 2019, 2018, and 2017, respectively, for changes in FAC recoveries.

Natural Gas Operating Statistics – Year Ended December 31,	2019				2018				2017
Natural Gas Sales – dekatherms (in millions):
Ameren Missouri:
Residential	7				7				6
Commercial	4				4				3
Industrial	1				1				1
Transport	9				9				8
Ameren Missouri total	21				21				18
Ameren Illinois Natural Gas:
Residential	61				60				50
Commercial	19				18				15
Industrial	4				4				3
Transport	101				100				98
Ameren Illinois Natural Gas total	185				182				166
Ameren total	206				203				184
Natural Gas Operating Revenues (in millions):
Ameren Missouri:
Residential	$	81			$	90			$	77
Commercial	34				37				31
Industrial	4				4				4
Transport and other	15				7				14
Ameren Missouri total	$	134			$	138			$	126
Ameren Illinois Natural Gas:
Residential	$	570			$	581			$	531
Commercial	154				159				146
Industrial	13				17				12
Transport and other	60				58				54
Ameren Illinois Natural Gas total	$	797			$	815			$	743
Other and intercompany eliminations	(2		)		(1		)		(2		)
Ameren total	$	929			$	952			$	867
Rate Base Statistics – At December 31,	2019				2018				2017
Rate Base (in billions):
Electric and natural gas transmission and distribution	$	12.8			$	11.3			$	10.1
Coal generation:
Labadie Energy Center	0.9				0.8				0.7
Sioux Energy Center	0.6				0.6				0.7
Rush Island Energy Center	0.5				0.4				0.4
Meramec Energy Center	0.1				0.2				0.2
Coal generation total	2.1				2.0				2.0
Nuclear generation	1.4				1.3				1.5
Renewable generation	0.5				0.5				0.4
Natural gas generation	0.4				0.4				0.4
Rate base total	$	17.2			$	15.5			$	14.4

AVAILABLE INFORMATION

The Ameren Companies make available free of charge through Ameren’s website (www.ameren.com) their annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and any amendments to those reports filed with or furnished to the SEC pursuant to Sections 13(a) or 15(d) of the Exchange Act as soon as reasonably possible after such reports are electronically filed with, or furnished to, the SEC. These documents are also available through the SEC’s website (www.sec.gov). Ameren’s website is a channel of distribution for material information about the Ameren Companies. Financial and other material information is routinely posted to, and accessible at, Ameren’s website.

The Ameren Companies also make available free of charge through Ameren’s website the charters of Ameren’s board of directors’ audit and risk committee, human resources committee, nominating and corporate governance committee, finance committee, and nuclear and operations committee; the corporate governance guidelines; a policy regarding communications to the board of directors; a policy and procedures document with respect to related-person transactions; a code of ethics for principal executive and senior financial officers; a code of business conduct applicable to all directors, officers and employees; and a director nomination policy that applies to the Ameren Companies. The information on Ameren’s website, or any other website referenced in this report, is not incorporated by reference into this report.