X0306 4 2020-03-02 0 0001370450 Willdan Group, Inc. WLDN 0001601038 McLaughlin Stacy B. 2401 EAST KATELLA AVENUE SUITE 300 ANAHEIM CA 92806 0 1 0 0 Chief Financial Officer Common Stock 2020-03-02 4 A 0 7010 0 A 13341 D Common Stock 2020-03-06 4 F 0 3187 32.68 D 10154 D Common Stock 2020-03-09 4 F 0 198 32.68 D 9956 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. Includes an aggregate of 706 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan, including 366 shares on June 30, 2019 and 340 shares on December 31, 2019. 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). Represents shares of the Issuer's Common Stock withheld for tax withholding purposes in connection with the vesting of restricted stock on March 8, 2020, which restricted stock was granted on March 8, 2017. /s/ Stacy B. McLaughlin 2020-03-12