SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

General

Ameren, headquartered in St. Louis, Missouri, is a public utility holding company under PUHCA 2005, administered by FERC. Ameren’s 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 parent company expenses by Ameren depend on distributions made to it by its subsidiaries. Ameren’s principal subsidiaries are listed below. Also see the Glossary of Terms and Abbreviations at the front of this report and in the Form 10-K.


•	Union Electric Company, doing business as Ameren Missouri, operates a rate-regulated electric generation, transmission, and distribution business, and a rate-regulated natural gas transmission and distribution business in Missouri. Ameren Missouri supplies electric service to 1.2 million customers and natural gas service to 127,000 customers.


•	Ameren Illinois Company, doing business as Ameren Illinois, operates a rate-regulated electric and natural gas transmission and distribution business in Illinois. Ameren Illinois supplies electric service to 1.2 million customers and natural gas service to 807,000 customers.

Ameren has various other subsidiaries responsible for activities such as the provision of shared services. Ameren also has a subsidiary, ATXI, that operates a FERC rate-regulated electric transmission business and is constructing the Illinois Rivers project.

The operating results, assets, and liabilities for New AER and the Elgin, Gibson City, Grand Tower, Meredosia, and Hutsonville energy centers have been presented separately as discontinued operations for all periods presented in this report. Unless otherwise stated, these notes to Ameren’s financial statements exclude discontinued operations for all periods presented. On January 31, 2014, Medina Valley completed its sale of the Elgin, Gibson City, and Grand Tower gas-fired energy centers to Rockland Capital. See Note 12 - Divestiture Transactions and Discontinued Operations in this report for additional information regarding the discontinued operations presentation and Note 16 - Divestiture Transactions and Discontinued Operations under Part II, Item 8, of the Form 10-K for additional information regarding Ameren’s divestiture of New AER in December 2013.

The financial statements of Ameren are prepared on a consolidated basis, and therefore include the accounts of its majority-owned subsidiaries. All significant intercompany transactions have been eliminated. Ameren Missouri and Ameren Illinois have no subsidiaries, and therefore their financial statements are not prepared on a consolidated basis. All tabular dollar amounts are in millions, unless otherwise indicated.

Our accounting policies conform to GAAP. Our financial statements reflect all adjustments (which include normal, recurring adjustments) that are necessary, in our opinion, for a fair presentation of our results. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions. Such estimates and assumptions affect reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the dates of financial statements, and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates. The results of operations of an interim period may not give a true indication of results that may be expected for a full year. These financial statements should be read in conjunction with the financial statements and the notes thereto included in the Form 10-K.

Earnings Per Share

Basic earnings per share is computed by dividing net income attributable to Ameren Corporation common stockholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per share is computed by dividing net income attributable to common stockholders by the diluted weighted-average number of common shares outstanding during the period. Diluted earnings per share reflects the potential dilution that would occur if certain stock-based performance share units were settled.

The following table presents Ameren’s basic and diluted earnings per share calculations and reconciles the weighted-average number of common shares outstanding to the diluted weighted-average number of common shares outstanding for the three and nine months ended September 30, 2014, and 2013:



	Three Months						Nine Months
	2014			2013			2014			2013
Net income (loss) attributable to Ameren Corporation:
Continuing operations	$	294		$	305		$	541		$	464
Discontinued operations	(1		)	(3		)	(3		)	(212		)
Net income attributable to Ameren Corporation	$	293		$	302		$	538		$	252

Average common shares outstanding - basic	242.6			242.6			242.6			242.6
Assumed settlement of performance share units	1.7			2.5			1.7			1.8
Average common shares outstanding - diluted	244.3			245.1			244.3			244.4

Earnings (loss) per common share – basic:
Continuing operations	$	1.21		$	1.26		$	2.23		$	1.92
Discontinued operations	—			(0.01		)	(0.01		)	(0.88		)
Earnings per common share – basic	$	1.21		$	1.25		$	2.22		$	1.04

Earnings (loss) per common share – diluted:
Continuing operations	$	1.20		$	1.25		$	2.21		$	1.91
Discontinued operations	—			(0.01		)	(0.01		)	(0.88		)
Earnings per common share – diluted	$	1.20		$	1.24		$	2.20		$	1.03

There were no potentially dilutive securities excluded from the diluted earnings per share calculations for the three and nine months ended September 30, 2014, and 2013.

Stock-based Compensation

Ameren’s long-term incentive plan available for eligible employees and directors, the 2006 Incentive Plan, was replaced prospectively for new grants by the 2014 Incentive Plan effective April 24, 2014. The 2014 Incentive Plan provides for a maximum of 8 million common shares to be available for grant to eligible employees and directors, and retains many of the features of the 2006 Incentive Plan. To the extent that the issuance of a share that is subject to an outstanding award under the 2006 Incentive Plan, as of April 24, 2014, would cause Ameren to exceed the maximum authorized shares under the 2006 Incentive Plan, the issuance of that share will take place under the 2014 Incentive Plan and will therefore reduce the maximum number of shares that may be granted under the 2014 Incentive Plan. The 2014 Incentive Plan awards may be stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance share units, cash-based awards, and other stock-based awards.

A summary of nonvested performance share units at September 30, 2014, and changes during the nine months ended September 30, 2014, under the 2006 Incentive Plan and the 2014 Incentive Plan are presented below:



	Performance Share Units
	Share Units		Weighted-average Fair Value Per Share Unit at Grant Date
Nonvested at January 1, 2014	1,218,544		$	33.23
Granted^(a)	685,026		38.90
April Grants^(b)	38,559		50.34
Forfeitures	(65,847	)	33.82
Vested^(c)	(123,295	)	38.64
Nonvested at September 30, 2014	1,752,987		$	35.42


(a)	Includes performance share units (share units) granted to certain executive and nonexecutive officers and other eligible employees in 2014 under the 2006 Incentive Plan and the 2014 Incentive Plan.

(b)

In April 2014, certain executive officers were granted additional share units under the 2006 Incentive Plan and the 2014 Incentive Plan. The significant assumptions used to calculate fair value included a prorated three-year risk-free rate ranging from 0.76% to 0.79%, volatility of 12% to 18% for the peer group, and Ameren’s attainment of a three-year average earnings per share threshold during the performance period.


(c)	Share units vested due to the attainment of retirement eligibility by certain employees. Actual shares issued for retirement-eligible employees will vary depending on actual performance over the three-year measurement period.

The fair value of each share unit awarded in 2014, excluding the April Grants, under the 2006 Incentive Plan and the 2014 Incentive Plan was determined to be $38.90. That amount was based on Ameren’s closing common share price of $36.16 at December 31, 2013, and lattice simulations. Lattice simulations are used to estimate expected share payout based on Ameren’s total stockholder return for a three-year performance period relative to the designated peer group beginning January 1, 2014. The simulations can produce a greater fair value for the share unit than the applicable closing common share price because they include the weighted payout scenarios in which an increase in the share price has occurred. The significant assumptions used to calculate fair value also included a three-year risk-free rate of 0.78%, volatility of 12% to 18% for the peer group, and Ameren’s attainment of a three-year average earnings per share threshold during the performance period.

Intangible Assets

Ameren and Ameren Missouri classify renewable energy credits and emission allowances as intangible assets. Ameren Illinois consumes renewable energy credits as they are purchased through the IPA procurement process and expenses them immediately. Ameren Missouri’s emission allowances are allocated by the EPA and therefore are recorded at zero cost. We evaluate intangible assets for impairment if events or changes in circumstances indicate that their carrying amount might be impaired.

At September 30, 2014, Ameren’s and Ameren Missouri’s intangible assets consisted of renewable energy credits obtained through wind and solar power purchase agreements. The book values of both Ameren’s and Ameren Missouri’s renewable energy credits were $20 million and $22 million at September 30, 2014 and December 31, 2013, respectively.

Ameren Missouri’s and Ameren Illinois’ renewable energy credits and Ameren Missouri’s emission allowances are charged to “Purchased power” expense and “Fuel” expense, respectively, as they are used in operations. The following table presents amortization expense based on usage of renewable energy credits and emission allowances, net of gains from sales, for Ameren, Ameren Missouri and Ameren Illinois, during the three and nine months ended September 30, 2014, and 2013:



		Three Months			Nine Months
	2014		2013		2014		2013
Ameren Missouri	$	1	$	—	$	7	$	(a)
Ameren Illinois		1		2		7		9
Ameren	$	2	$	2	$	14	$	9


(a)	Less than $1 million.

Excise Taxes

Excise taxes levied on us are reflected on Ameren Missouri electric customer bills and on Ameren Missouri and Ameren Illinois natural gas customer bills. They are recorded gross in “Operating Revenues - Electric,” “Operating Revenues - Gas” and “Operating Expenses - Taxes other than income taxes” on the statement of income or the statement of income and comprehensive income. Excise taxes reflected on Ameren Illinois electric customer bills are imposed on the customer and are therefore not included in revenues and expenses. They are included in “Taxes accrued” on the balance sheet. The following table presents excise taxes recorded in “Operating Revenues - Electric,” “Operating Revenues - Gas” and “Operating Expenses - Taxes other than income taxes” for the three and nine months ended September 30, 2014, and 2013:



	Three Months				Nine Months
	2014		2013		2014		2013
Ameren Missouri	$	47	$	49	$	120	$	120
Ameren Illinois	9		10		46		43
Ameren	$	56	$	59	$	166	$	163

Uncertain Tax Positions

With the adoption of new accounting guidance in the first quarter of 2014, unrecognized tax benefits are recorded as a reduction to the deferred tax assets for net operating losses and tax credit carryforwards within “Accumulated deferred income taxes, net” on our balance sheets. Unrecognized tax benefits that exceed these carryforwards are recorded in “Other deferred credits and liabilities” on our balance sheets. At September 30, 2014, unrecognized tax benefits of $89 million, $13 million, and $2 million were recorded in “Accumulated deferred income taxes, net” on Ameren's, Ameren Missouri's and Ameren Illinois' balance sheets, respectively. At December 31, 2013, unrecognized tax benefits of $84 million, $15 million, and $- million previously recorded in “Other deferred credits and liabilities” on Ameren’s, Ameren Missouri’s and Ameren Illinois’ respective balance sheets were reclassified to “Accumulated deferred income taxes, net” for comparative purposes. For additional information see the Accounting and Reporting Developments section below.

The following table presents the total amount of reserves for unrecognized tax benefits (detriments) related to uncertain tax positions as of September 30, 2014, and December 31, 2013:



	September 30, 2014		December 31, 2013
Ameren	$	97	$	90
Ameren Missouri	35		31
Ameren Illinois	1		(1		)

The following table presents the amount of reserves for unrecognized tax benefits, included in the table above, related to uncertain tax positions that would impact results of operations, if recognized, as of September 30, 2014, and December 31, 2013:



	September 30, 2014		December 31, 2013
Ameren	$	55	$	54
Ameren Missouri	3		3
Ameren Illinois	—		—

In October 2014, a settlement was reached with the Appeals Office of the IRS for the years 2007 through 2010. During the fourth quarter of 2014, this settlement, which is primarily related to uncertain tax positions associated with the timing of research tax deductions, will result in a decrease in Ameren’s uncertain tax benefits of $16 million, of which $9 million is related to Ameren Missouri. This settlement will not have a material impact on Ameren’s or Ameren Missouri’s results of operations or liquidity.

Ameren’s federal income tax returns for the years 2011 and 2012 are before the Appeals Office of the IRS. It is reasonably possible that a settlement will be reached with the Appeals Office of the IRS in the next 12 months for the years 2011 and 2012. The potential settlement, which would primarily relate to uncertain tax positions associated with the timing of research tax deductions, is expected to result in a decrease in Ameren’s uncertain tax benefits of $6 million, all of which relates to Ameren Missouri and none of which will have a material impact on their respective results of operations or liquidity.

Ameren’s federal income tax return for the year 2013 is currently under examination by the IRS and it is reasonably possible that a settlement will be reached with the IRS examination team in the next 12 months for that year. The potential settlement, which would relate to the timing of research tax deductions and the tax basis of certain leases related to the divestiture of the merchant generation business, is expected to result in a decrease in Ameren’s uncertain tax benefits of $73 million, of which $17 million relates to Ameren Missouri and $1 million relates to Ameren Illinois. Although we are unable to estimate the impact of any potential settlement at this time, up to $55 million of the Ameren total could increase net income from Ameren’s discontinued operations. Settlement of the remaining $18 million of uncertain tax positions at Ameren, as well as those positions at Ameren Missouri and Ameren Illinois, are associated with the timing of deductions and will not have a material impact on our results of operations.

In addition, it is reasonably possible that other events will occur during the next 12 months that would cause the total amount of our unrecognized tax benefits to fluctuate. However, other than as described above, we do not believe any such fluctuations would be material to our results of operations, financial position, or liquidity.

State income tax returns are generally subject to examination for a period of three years after filing of the return. We do not currently have material state income tax issues under examination, administrative appeals, or litigation. The state impact of any federal changes remains subject to examination by various states for a period of up to one year after formal notification to the states.

Asset Retirement Obligations

AROs at Ameren, Ameren Missouri and Ameren Illinois increased at September 30, 2014, compared to December 31, 2013, to reflect the accretion of obligations to their fair value and an additional ARO at Ameren and Ameren Missouri of $2 million related to the retirement costs for a CCR storage facility, partially offset by immaterial settlements.

Noncontrolling Interests

As of September 30, 2014, Ameren's noncontrolling interests were composed of the preferred stock not subject to mandatory redemption of Ameren Missouri and Ameren Illinois. All noncontrolling interests are classified as a component of equity separate from Ameren's equity on its consolidated balance sheet. A reconciliation of the equity changes attributable to the noncontrolling interests at Ameren for the three and nine months ended September 30, 2014, and 2013, are shown below:



	Three Months							Nine Months
	2014			2013				2014			2013
Noncontrolling interests, beginning of period	$	142		$	151		^(a)	$	142		$	151		^(a)
Net income from continuing operations attributable to noncontrolling interests	2			2				5			5
Dividends paid to noncontrolling interest holders	(2		)	(2		)		(5		)	(5		)
Noncontrolling interests, end of period	$	142		$	151		^(a)	$	142		$	151		^(a)

(a)

Included the 20% EEI ownership interest not owned by Ameren prior to the divestiture of New AER to IPH. Prior to the divestiture of New AER, the assets and liabilities of EEI were consolidated in Ameren’s balance sheet at a 100% ownership level and were included in “Assets of discontinued operations” and “Liabilities of discontinued operations,” respectively. The divestiture of New AER, which included EEI, was completed in the fourth quarter of 2013. See Note 12 - Divestiture Transactions and Discontinued Operations for additional information.

Accounting and Reporting Developments

The following is a summary of recently adopted or issued authoritative accounting guidance relevant to the Ameren Companies.

Presentation of an Unrecognized Tax Benefit

In July 2013, FASB issued additional authoritative accounting guidance to provide clarity for the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The objective of this guidance is to eliminate diversity in practice related to the presentation of certain unrecognized tax benefits. It requires entities to present an unrecognized tax benefit as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward to the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is available under the tax law. This guidance was effective for the Ameren Companies beginning in the first quarter of 2014. Previously, unrecognized tax benefits were recorded in “Other deferred credits and liabilities” on Ameren's, Ameren Missouri's and Ameren Illinois' respective balance sheets. Beginning in the first quarter 2014, unrecognized tax benefits are recorded as a reduction to the deferred tax assets for net operating losses and tax credit carryforwards within “Accumulated deferred income taxes, net” on our balance sheets. Unrecognized tax benefits that exceed these carryforwards are recorded in “Other deferred credits and liabilities,” on the respective balance sheets. For comparative purposes, the Ameren Companies reclassified the December 31, 2013 balances in accordance with the new guidance as discussed in the Uncertain Tax Positions section above. The implementation of the additional authoritative accounting guidance did not affect the Ameren Companies' results of operations or liquidity, as this guidance is presentation-related only.

Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity

In April 2014, FASB issued authoritative accounting guidance that changes the criteria for reporting and qualifying for discontinued operations. Under the new guidance, a component of an entity, or a group of components of an entity, that either meets the criteria to be classified as held for sale or is disposed of by sale or otherwise, is required to be reported in discontinued operations if the disposal represents a strategic shift that has or will have a major effect on an entity’s operations and financial results. The guidance includes expanded disclosure requirements for discontinued operations and additional disclosures about a disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation. The guidance will be effective for the Ameren Companies in the first quarter of 2015 for components that are classified as held for sale or disposed of on or after January 1, 2015. Early adoption is permitted, but only for disposals or classifications as held for sale that have not been reported in financial statements previously issued. Therefore, Ameren’s existing discontinued operations would not be subject to the new disclosure requirements. The guidance will not affect the Ameren Companies’ results of operations, financial position, or liquidity, as this guidance is presentation-related only.

Revenue from Contracts with Customers

In May 2014, FASB issued authoritative accounting guidance to clarify the principles for recognizing revenue and to develop a common revenue standard for GAAP. The guidance requires an entity to recognize an amount of revenue for the transfer of promised goods or services to customers that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires additional disclosures to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The guidance will be effective for the Ameren Companies in the first quarter of 2017. The Ameren Companies are currently assessing the impacts of this guidance.