UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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): October 1, 2012

ZAYO GROUP, LLC

(Exact name of registrant as specified in its charter)

400 Centennial Parkway, Suite 200, Louisville, CO 80027

(Address of Principal Executive Offices)

(303) 381-4683

(Registrant’s Telephone Number, Including Area Code)

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

Section 7 – Regulation FD

As previously disclosed in a Current Report on Form 8-K filed by the Company with the Securities and Exchange Commission (“SEC”) on August 16, 2012, the Company entered into a Unit Purchase Agreement (the “Agreement”) to acquire all remaining ownership units of USCarrier Telecom, LLC (“USCarrier”). On October 1, 2012, the transaction contemplated by the Agreement was consummated at which time the Company acquired 100 percent of the outstanding equity interest in USCarrier for a purchase price of $15.9 million, subject to certain post-closing adjustments. As part of the Agreement, the Company agreed to assume approximately $10.1 million in debt and acquired $7.8 million in cash. The full amount of the assumed debt was paid off by the Company as part of the closing funds flow. The acquisition was funded with cash on hand.

The Company issued a press release on October 2, 2012 announcing the closing of the Agreement. A copy of the press release is filed as Exhibit 99.1 to this filing on Form 8-K and is incorporated by reference in this Item 7.01.

(d) Exhibits. The following exhibit is furnished with this Form 8-K:

The information contained under Item 7.01 and 9.01 of this filing on Form 8-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, and shall not be deemed incorporated by reference in any filing with the Securities and Exchange Commission under the Securities Exchange Act of 1934 or the Securities Act of 1933, whether made before or after the date hereof and irrespective of any general incorporation language in any filings.

Portions of this report may constitute “forward-looking statements” as defined by federal law. Although the Company believes any such statements are based on reasonable assumptions, there is no assurance that actual outcomes will not be materially different. Additional information about issues that could lead to material changes in the Company’s performance is contained in the Company’s filings with the Securities and Exchange Commission. The Company undertakes no obligation to publicly update or revise any forward-looking statements to reflect events or circumstances after the date hereof.

Investors should take into consideration, with respect to the Company, those risks and uncertainties discussed in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2012 on Form 10-K filed with the SEC on September 14, 2012, including those under the heading “Risk Factors.”

SIGNATURE

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.

DATED: October 2, 2012

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