X0306 4 2020-03-02 0 0001370450 Willdan Group, Inc. WLDN 0001452377 Chow Daniel 2401 EAST KATELLA AVE SUITE 300 ANAHEIM CA 92806 0 1 0 0 Chief Operating Officer Common Stock 2020-03-02 4 A 0 8763 0 A 40873 D Common Stock 2020-03-06 4 F 0 3129 32.68 D 37744 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 8,760 shares of Common Stock. Includes 889 shares of restricted stock that vest on October 31, 2020. 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). /s/ Stacy McLaughlin, Attorney-in-fact for Daniel Chow 2020-03-12