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

Date of report (Date of earliest event reported): January 16, 2014

EnerNOC, Inc.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (617) 224-9900

N/A

(Former Name or Former Address, if Changed Since Last Report)

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 (see General Instruction A.2. below):

On January 16, 2014, EnerNOC, Inc. (the “Company”) entered into a Third Amendment to Credit Agreement (the “Third Amendment”) to its $70 million senior secured revolving credit facility (the “Credit Agreement”) with the several lenders from time to time party thereto and Silicon Valley Bank, as administrative agent, swingline lender, issuing lender, lead arranger and book manager (“SVB” and together with the other lenders, the “Lenders”), dated April 18, 2013. The Third Amendment provides for lessening of certain restrictions on the ability of the Company and its subsidiaries to acquire other entities, incur additional indebtedness, enter into transactions with affiliates, transfer assets, and repurchase common stock of the Company. In addition, the Third Amendment provides for a decrease to the minimum free cash flow financial covenant that the Company is required to meet.

On December 3, 2013, the Company previously entered into an immaterial amendment (the “Second Amendment”) to the Credit Agreement, providing for the licensing of intellectual property rights to one of the Company’s subsidiaries and the lessening of a restriction on the ability of the Company and its subsidiaries to make certain permitted investments.

The foregoing summary of the Third Amendment and the Second Amendment does not purport to be complete and is qualified in its entirety by reference to the Third Amendment and the Second Amendment, copies of which are attached as Exhibit 10.1 and Exhibit 10.2, respectively, to this Current Report on Form 8-K and are incorporated herein by reference.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth in Item 1.01 above is hereby incorporated by reference in this Item 2.03.

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SIGNATURES

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

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EXHIBIT INDEX

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