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): August 16, 2016

U.S. Silica Holdings, Inc.

(Exact name of registrant as specified in its charter)

Delaware

(State or other jurisdiction of incorporation)

Registrant’s telephone number, including area code: (301) 682-0600

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:

On August 16, 2016, U.S. Silica Holdings, Inc., a Delaware corporation (the “Company”), completed the acquisition of New Birmingham, Inc., a Nevada corporation (“NBI”), pursuant to the terms of the previously announced Agreement and Plan of Merger, by and among the Company, New Birmingham Merger Corp., a Nevada corporation and wholly owned subsidiary of the Company (“Merger Sub 1”), NBI Merger Subsidiary II, Inc., a Delaware corporation and wholly owned subsidiary of the Company (“Merger Sub 2”), NBI, and each of David Durrett and Erik Dall as representatives of the sellers and optionholders (the “Merger Agreement”), pursuant to which the Company acquired all of the outstanding capital stock of NBI through the merger of Merger Sub 1 with and into NBI, followed immediately by the merger of NBI with and into Merger Sub 2 (collectively, the “Merger”). The consideration paid by the Company to the stockholders of NBI at the closing of the Merger consisted of $106,500,000 of cash, subject to customary post-closing adjustment, 2,630,513 shares of common stock of the Company and assumed liabilities. A portion of the cash consideration has been deposited into escrow to support the post-closing purchase price adjustment and the sellers’ indemnification obligations. The stockholders of NBI are subject to a 45 day lock-up period from August 16, 2016 pursuant to which they are generally prohibited from selling or otherwise disposing of shares of the Company’s common stock issued as consideration in the Merger. The Company has agreed to file a shelf registration statement with the Securities and Exchange Commission to enable the stockholders of NBI to resell the shares of the Company’s common stock following the lock-up period.

The foregoing description of the Merger Agreement does not purport to be complete and is qualified in its entirety by reference to the Merger Agreement. A copy of the Merger Agreement will be filed as an exhibit to the Company’s Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2016.

The Company intends to file any financial statements that may be required by Item 9.01(a) of Form 8-K with respect to the Merger within 71 calendar days after the date that this Form 8-K was required to be filed pursuant to Item 9.01(a)(4) of Form 8-K.

As described under Item 1.01 above (the content of which is incorporated herein by reference), at the closing of the Merger, the Company issued 2,630,513 shares of its common stock to the stockholders of NBI. The shares were issued pursuant to the exemption from registration provided in Section 4(a)(2) and Regulation D (Rule 506(b)) under the Securities Act of 1933, as amended, as a transaction by an issuer not involving a public offering.

On August 17, 2016, the Company issued a press release announcing that it had completed the Merger. A copy of the press release is attached hereto as Exhibit 99.1.

Cautionary Language Regarding Forward-Looking Statements

Except for the historical information contained herein, certain of the matters discussed in this communication constitute “forward-looking statements” within the meaning of the Securities Act of 1933 and the Securities Exchange Act of 1934, both as amended by the Private Securities Litigation Reform Act of 1995. Words such as “may,” “will,” “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “target,” “forecast,” and words and terms of similar substance used in connection with any

discussion of future plans, actions, or events identify forward-looking statements. These forward-looking statements include, but are not limited to, statements regarding benefits of the Merger and anticipated future financial and operating performance and results, including estimates for growth. These statements are based on the current expectations of management of the Company. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this communication. For example, (1) problems may arise in successfully integrating the businesses of the companies, which may result in the combined company not operating as effectively and efficiently as expected; (2) the industry may be subject to future regulatory or legislative actions that could adversely affect the companies; and (3) the companies may be adversely affected by other economic, business, and/or competitive factors. Other unknown or unpredictable factors could also have material adverse effects on future results, performance or achievements of the combined company. Discussions of some of these other important factors and assumptions are contained in the Company’s filings with the Securities and Exchange Commission (SEC), and available at the SEC’s website at www.sec.gov, including (1) the Company’s 2015 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; and (2) the Company’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2016 in (a) Part II, Other Information, Item 1A. Risk Factors, (b) Part I, 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. In light of these risks, uncertainties, assumptions and factors, the forward-looking events discussed in this communication may not occur. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this communication. The Company does not undertake any obligation to publicly release any revision to its forward-looking statements to reflect events or circumstances after the date of this communication.

(a) Financial statements of the business acquired.

The Company intends to file any financial statements that may be required by Item 9.01(a) of Form 8-K with respect to the Merger within 71 calendar days after the date that this Form 8-K was required to be filed pursuant to Item 9.01(a)(4) of Form 8-K.

(b) Pro forma financial information.

The Company intends to file the pro forma financial information required by Item 9.01(b) of Form 8-K with respect to the Merger within 71 calendar days after the date that this Form 8-K was required to be filed pursuant to Item 9.01(b)(2) of Form 8-K.

(d) Exhibits.

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.

Date: August 18, 2016

EXHIBIT INDEX