As filed with the Securities and Exchange Commission on June 12, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

BARRETT BUSINESS SERVICES, INC.

(Exact name of registrant as specified in its charter)

BARRETT BUSINESS SERVICES, INC. SECOND AMENDED AND RESTATED 2020 STOCK INCENTIVE PLAN

(Full title of the plan)

Gary E. Kramer

Chief Executive Officer

Barrett Business Services, Inc.

8100 NE Parkway Drive

Vancouver, Washington 98662

Telephone (360) 828-0700

(Name, address, and telephone number of agent for service)

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

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 7(a)(2)(B) of the Securities Act. 

REGISTRATION OF ADDITIONAL SHARES PURSUANT TO GENERAL INSTRUCTION E

Pursuant to General Instruction E of Form S-8, Barrett Business Services, Inc. (the “Registrant”), is filing this Registration Statement with the Securities and Exchange Commission (the “SEC”) under the Securities Act of 1933, as amended (the “Securities Act”), to register an additional 1,200,000 shares of Common Stock, par value $0.01 per share (the “Common Stock”) issuable under the Registrant’s Second Amended and Restated 2020 Stock Incentive Plan. This Registration Statement hereby incorporates by reference the contents of the Registrant’s registration statements on Form S-8 filed with the SEC on June 26, 2020 (File No. 333-239460), relating to 1,500,000 shares of Common Stock, and on June 27, 2023 (File No. 333-272945), relating to 1,400,000 shares of Common Stock, to the extent not modified or superseded hereby or by any subsequently filed document that is incorporated by reference herein or therein. All share numbers have been adjusted for the four-for-one stock split of the Common Stock on June 4, 2024.

The information specified in the instructional note to Part I of Form S-8 has been omitted from this Registration Statement.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The following documents filed by the Registrant with the SEC are incorporated by reference in this Registration Statement:

Except to the extent that information is deemed furnished and not filed pursuant to securities laws and regulations, all documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934, as amended, subsequent to the date hereof and prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall also be deemed to be incorporated by reference herein and to be a part hereof from the dates of filing of such documents.

Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

Item 8. Exhibits.

SIGNATURES

The Registrant.

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the city of Vancouver, state of Washington, on the 12th day of June, 2026.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities indicated as of the 12th day of June, 2026.