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): May 21, 2015

TRINET GROUP, INC.

(Exact name of Registrant as Specified in Its Charter)

Registrant’s Telephone Number, Including Area Code: (510) 352-5000

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 May 21, 2015, TriNet Group, Inc. (the “Company”) held its 2015 Annual Meeting of Stockholders (the “Annual Meeting”) at the offices of the Company at 1100 San Leandro Blvd., Suite 400, San Leandro, CA 94577. At the Annual Meeting, the Company’s stockholders voted on four proposals, each of which is described in more detail in the Company’s definitive proxy statement on Schedule 14A filed with the U.S. Securities and Exchange Commission on April 2, 2015. The following is a brief description of each matter voted upon and the certified results, including the number of votes cast for and against each matter and, if applicable, the number of abstentions and broker non-votes with respect to each matter.

Proposal 1. Stockholders elected each of the three nominees for Class I director to serve until the Company’s 2018 Annual Meeting of Stockholders or until his or her respective successor has been duly elected and qualified. The voting results were as follows:

Proposal 2. Stockholders approved, on an advisory basis, the compensation of the Company’s named executive officers. The voting results were as follows:

Proposal 3. Stockholders indicated, on an advisory basis, a preferred frequency of stockholder advisory votes on the compensation of the Company’s named executive officers of every one year. The voting results were as follows:

Proposal 4. Stockholders ratified the selection by the Audit Committee of the Board of Directors of the Company of Ernst & Young LLP as the Company’s independent registered public accounting firm for the year ending December 31, 2015. The voting results were as follows:

Board Decision Regarding Frequency of Stockholder Advisory Vote on Executive Compensation

Based on the voting results of the Annual Meeting, and its consideration of the appropriate voting frequency for the Company at this time, the Board of Directors of the Company has decided that it will include an advisory stockholder vote on the compensation of the Company’s named executive officers in its proxy materials every year until the next advisory vote on the frequency of stockholder votes on executive compensation, which is required to occur no later than the Annual Meeting of Stockholders in 2021.

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.