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): March 15, 2018

BARRETT BUSINESS SERVICES, INC.

(Exact name of registrant as specified in charter)

Registrant’s telephone number, including area code: (360) 828-0700

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:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 1.01 Entry into a Material Definitive Agreement.

The disclosure included under Item 2.03 is incorporated by reference.

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

On March 15, 2018, Barrett Business Services, Inc. (the "Company"), entered into a First Amendment (the "Amendment") to its Amended and Restated Credit Agreement dated as of June 30, 2017 (the "Credit Agreement"), with its principal bank, Wells Fargo Bank, National Association. The Amendment increases the revolving credit line under the Credit Agreement from $25,000,000 to $40,000,000 during the period from March 15, 2018, through June 15, 2018, reverting to $25,000,000 from June 16, 2018, through the expiration of the revolving credit line on July 1, 2018. All other terms and conditions of the Credit Agreement are unchanged, as described in Note 6 to the Company's audited consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2017, filed by the Company with the Securities and Exchange Commission on March 6, 2018, and incorporated herein by reference.

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 thereunto duly authorized.