UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

June 1, 2015

Date of Report (Date of earliest event reported)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Section 8 – Other Events

Item 8.01 Other Events.

On June 1, 2015, Exelon Corporation (Exelon) and Exelon Generation Company LLC (Generation) concluded that the proposed Low Carbon Portfolio Standard (LCPS) legislation would not be enacted by the Illinois General Assembly during the current legislative session, even though the session has been extended. Exelon and Generation intend to continue their dialogue with Illinois policymakers regarding policy reforms which would better recognize the full value that Generation’s nuclear plants provide for Illinois. Exelon and Generation will also continue to evaluate the current and expected economics of each of Generation’s Illinois nuclear plants. In September, Generation has an obligation to inform PJM Interconnection LLC (PJM), the organization which administers capacity auctions, if any of its plants in the PJM region will not be participating in the May 2016 PJM capacity auction. In December, Generation must inform the Midcontinent Independent System Operator (MISO) if the Clinton plant will not be in operation during the next MISO resource adequacy planning year that begins June 1, 2016. Exelon and Generation have not made any decisions regarding potential plant closures at this time.

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This combined Form 8-K is being furnished separately by Exelon Corporation and Exelon Generation Company, LLC (the “Registrants”). Information contained herein relating to any individual Registrant has been furnished by such Registrant on its own behalf. No Registrant makes any representation as to information relating to any other Registrant.

This Current Report includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks and uncertainties. The factors that could cause actual results to differ materially from these forward-looking statements include those discussed herein as well as those discussed in (1) Exelon’s 2014 Annual Report on Form 10-K in (a) ITEM 1A. Risk Factors, (b) ITEM 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations and (c) ITEM 8. Financial Statements and Supplementary Data: Note 22; (2) Exelon’s First Quarter 2015 Quarterly Report on Form 10-Q in (a) Part II, Other Information, ITEM 1A. Risk Factors; (b) Part 1, Financial Information, ITEM 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations and (c) Part I, Financial Information, ITEM 1. Financial Statements: Note 17; and (3) other factors discussed in filings with the Securities and Exchange Commission by the Registrants. Readers are cautioned not to place undue reliance on these forward-looking statements, which apply only as of the date of this Current Report. None of the Registrants undertakes any obligation to publicly release any revision to its forward-looking statements to reflect events or circumstances after the date of this Current Report.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, each Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

June 1, 2015

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