Summary of Significant Accounting Policies (EME and Midwest Generation, except as noted)

Chapter 11 Cases

EME and Midwest Generation continue to experience operating losses due to low realized energy and capacity prices, high fuel costs, and low generation at the Midwest Generation plants. These operating losses are a continuation of trends initially experienced in the fourth quarter of 2011. These adverse trends coupled with pending interest payments and the need to retrofit the Midwest Generation plants to comply with governmental regulations were expected to exhaust EME's and Midwest Generation's liquidity. Consequently, on December 17, 2012, EME and 16 of its wholly owned subsidiaries, Camino Energy Company, Chestnut Ridge Energy Company, Edison Mission Energy Fuel Services, LLC, Edison Mission Fuel Resources, Inc., Edison Mission Fuel Transportation, Inc., Edison Mission Holdings Co., Edison Mission Midwest Holdings Co., Midwest Finance Corp., Midwest Generation EME, LLC, Midwest Generation, Midwest Generation Procurement Services, LLC, Midwest Peaker Holdings, Inc., Mission Energy Westside, Inc., San Joaquin Energy Company, Southern Sierra Energy Company, and Western Sierra Energy Company (the Initial Debtors) filed voluntary petitions for relief under Chapter 11 of the Bankruptcy Code. On May 2, 2013, 3 additional EME subsidiaries, EME Homer City Generation L.P. (Homer City), Homer City Property Holdings Inc., and Edison Mission Finance Company (collectively, the Homer City Debtors) filed voluntary petitions for relief under Chapter 11 of the Bankruptcy Code. The Initial Debtors' chapter 11 cases and the Homer City Debtors' chapter 11 cases (collectively, the Chapter 11 Cases) are being jointly administered under case No. 12-49219 (JPC). The Initial Debtors and the Homer City Debtors are collectively referred to as the Debtor Entities.

The Debtor Entities remain in possession of their property and continue their business operations uninterrupted as "debtors-in-possession" under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provisions of the Bankruptcy Code and orders of the Bankruptcy Court. Other than the Debtor Entities, none of EME's other direct or indirect subsidiaries is a debtor in the Chapter 11 Cases. The filing of the Chapter 11 Cases automatically stayed most actions against the Debtor Entities, including actions to enforce the payment of EME's $3.7 billion of unsecured senior notes and Midwest Generation's obligations related to leases of the Powerton Station and Units 7 and 8 of the Joliet Station (the Powerton and Joliet Sale Leaseback). Absent an order from the Bankruptcy Court, substantially all of the Debtor Entities' pre-petition liabilities are subject to settlement under a reorganization plan.

The Bankruptcy Court established June 17, 2013 as the bar date for filing proofs of claim against the Initial Debtors estates. The bar date for the Homer City Debtors has not yet been established. The differences between amounts recorded by the Debtor Entities and the proofs of claims filed by creditors are investigated and resolved through the claims resolution process. This process may take considerable time to complete. The resolution of such claims could result in material adjustments to EME or Midwest Generation's financial statements. For further discussion, see Note 14—Restructuring Activities—Claims.

The filing of the Chapter 11 Cases constitutes an event of default under the Powerton and Joliet Sale Leaseback and under instruments governing the Senior Lease Obligation Bonds issued to finance these leases. EME, Midwest Generation, the owner-lessors, and certain of the holders of the pass-through certificates of Midwest Generation's lessor debt (the Certificate Holders) have been engaged in ongoing discussions regarding the ultimate disposition of the leases. In June 2013, EME and Midwest Generation agreed, among other things, to make monthly rental payments of $3.75 million beginning in July 2013 and to pay certain professional fees for the owner-lessors and Certificate Holders in exchange for an extension of the deadline to assume or reject the Powerton and Joliet leases and the agreement of the Certificate Holders to forbear and to direct the lease indenture trustee and pass-through trustee to forbear from seeking payment of any administrative claim for rent under the Powerton and Joliet leases (except the monthly partial rental payments of $3.75 million under the agreement) before the earlier of the effective date of a chapter 11 plan for Midwest Generation or a sale of substantially all of the assets of Midwest Generation. The parties filed a motion detailing the terms of this agreement and the Bankruptcy Court approved the extension of the statutory deadline by which the Debtor Entities must assume or reject the Powerton and Joliet leases until September 30, 2013.

The Chapter 11 Cases could also potentially give rise to counterparty rights and remedies under other documents. For further discussion, see Note 5—Debt and Credit Agreements and Note 9—Commitments and Contingencies—Lease Commitments—Powerton and Joliet Sale Leaseback.

The accompanying consolidated financial statements have been prepared assuming that EME and Midwest Generation will continue as going concerns. Financial statements prepared on this basis assume the realization of assets and the satisfaction of liabilities in the normal course of business for the 12-month period following the date of the financial statements. The accompanying consolidated financial statements do not include any adjustments related to the recoverability and classification of assets or the amounts and classification of liabilities or any other adjustments that might be necessary if EME and Midwest Generation were unable to continue as going concerns. EME and Midwest Generation are currently developing a plan for their restructuring, but there is no assurance such a plan will be successfully implemented. EME's and Midwest Generation's ability to continue as going concerns is dependent on many factors, including the successful development of a confirmed plan of reorganization and an emergence from bankruptcy. Uncertainty as to the outcome of these factors raises substantial doubt about EME's and Midwest Generation's ability to continue as going concerns.

Basis of Presentation

There are no material updates to EME's and Midwest Generation's significant accounting policies since the filing of EME's and Midwest Generation's combined annual report on Form 10-K for the year ended December 31, 2012, with the exception of new accounting principles adopted as discussed below in "—New Accounting Guidance." This quarterly report should be read in conjunction with the financial statements and notes included in EME's and Midwest Generation's combined annual report on Form 10-K for the year ended December 31, 2012.

In the opinion of management, all adjustments, consisting of recurring accruals, have been made that are necessary to fairly state the consolidated financial position and results of operations and cash flows in accordance with accounting principles generally accepted in the United States of America (GAAP) for the periods covered by this quarterly report on Form 10-Q. The results of operations for the three- and six-month periods ended June 30, 2013 are not necessarily indicative of the operating results for the full year. Except as indicated, amounts reflected in the notes to the consolidated financial statements relate to continuing operations of EME and Midwest Generation. Certain prior period amounts have been reclassified to conform to the current year financial statement presentation pertaining to discontinued operations.

Cash Equivalents

Cash equivalents included money market funds totaling $856 million and $615 million for EME and $99 million and $75 million for Midwest Generation at June 30, 2013 and December 31, 2012, respectively. The carrying value of cash equivalents equals the fair value as all investments have original maturities of less than three months.

Inventory

Inventory consisted of the following:



	EME				Midwest Generation
(in millions)	June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012
Coal, fuel oil and other raw materials	$	62	$	123	$	59	$	119
Spare parts, materials and supplies	59		52		45		46
Total inventory	$	121	$	175	$	104	$	165

Notes Receivable from EME (Midwest Generation only)

Notes receivable from EME on Midwest Generation's consolidated balance sheets consisted of the following:



	June 30, 2013							December 31, 2012
(in millions)	Carrying Value		Valuation Allowance			Net		Carrying Value		Valuation Allowance			Net
Current portion of notes receivable from affiliate	$	19	$	(19	)	$	—	$	12	$	(12	)	$	—
Interest receivable from affiliate	55		(55		)	—		55		(55		)	—
Notes receivable from affiliate	1,304		(1,304		)	—		1,311		(1,311		)	—
Total	$	1,378	$	(1,378	)	$	—	$	1,378	$	(1,378	)	$	—

As a result of the Chapter 11 Cases, EME did not make the scheduled principal and interest payment of $61 million due to Midwest Generation on January 2, 2013 and Midwest Generation recorded a full valuation allowance against its intercompany loan with EME during the fourth quarter of 2012. At December 31, 2012, Midwest Generation ceased accruing interest income associated with the intercompany loan as future payments, if any, made by EME under the loan will be dependent upon the overall resolution of the Chapter 11 Cases. Interest income from affiliates, included in interest and other income on Midwest Generation's consolidated statements of operations, was none and $27 million during the three months ended June 30, 2013 and 2012, respectively, and none and $55 million during the six months ended June 30, 2013 and 2012, respectively.

New Accounting Guidance

Accounting Guidance Adopted in 2013

Offsetting Assets and Liabilities

In December 2011 and December 2012, the Financial Accounting Standards Board (FASB) issued accounting standards updates modifying the disclosure requirements about the nature of an entity's rights of offsetting assets and liabilities in the consolidated balance sheet under master netting agreements and related arrangements associated with financial and derivative instruments. The guidance requires increased disclosure of the gross and net recognized assets and liabilities, collateral positions, and narrative descriptions of setoff rights. EME and Midwest Generation adopted this guidance effective January 1, 2013.

Presentation of Items Reclassified out of Accumulated Other Comprehensive Income

In February 2013, the FASB issued an accounting standards update which requires disclosure related to items reclassified out of accumulated other comprehensive income (AOCI). The guidance requires entities to present separately, for each component of other comprehensive income (OCI), current period reclassifications and the remainder of the current-period OCI. In addition, for certain current period reclassifications, an entity is required to disclose the effect of the item reclassified out of AOCI on the respective line item of net income. EME adopted this guidance effective January 1, 2013.

Accounting Guidance Not Yet Adopted

Joint and Several Liabilities

In February 2013, the FASB issued an accounting standard update which modifies the requirements for the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. The guidance requires companies to measure these obligations as the sum of the amount the company has agreed with co-obligors to pay and any additional amount it expects to pay on behalf of one or more co-obligors. This guidance is effective for fiscal years beginning after December 31, 2013. EME and Midwest Generation do not expect this guidance to have a material impact on results of operations.

Presentation of Unrecognized Tax Benefits

In July 2013, the FASB issued an accounting standard update which clarifies that a liability for an unrecognized tax benefit should be presented as a reduction of a deferred tax asset when settlement of the liability with the taxing authority results in the reduction of a net operating loss or tax credit carryforward. The requirement to record a non-cash settlement in a net manner does not affect EME and Midwest Generation's analysis of the realization of deferred tax assets. This guidance is effective for fiscal years beginning after December 31, 2013. EME and Midwest Generation do not expect this guidance to have a material impact on results of operations.