X0306 4 2020-03-02 0 0001370450 Willdan Group, Inc. WLDN 0001733678 CHEN MICAH 2401 E. KATELLA AVE SUITE 300 ANAHEIM CA 92806 0 1 0 0 General Counsel Common Stock 2020-03-02 4 A 0 7010 0 A 11791 D Common Stock 2020-03-06 4 F 0 2531 32.68 D 9260 D Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on March 6, 2018. The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on March 2, 2020, resulting in the immediate vesting of the restricted stock units as to 7,010 shares of Common Stock. Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of the performance-based restricted stock units referenced in footnote (1). Includes 281 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on December 31, 2019. /s/ Stacy McLaughlin, Attorney-in-fact for Micah Chen 2020-03-12