X0609 4 2026-03-20 0001370450 Willdan Group, Inc. WLDN 0001270606 BIEBER MICHAEL A false 2401 EAST KATELLA AVENUE SUITE 300 ANAHEIM CA 92806 true true false false PRESIDENT AND CEO 0 Common Stock 2026-03-20 4 F 0 2387 75.52 D 240219 D Represents shares of the Issuer's Common Stock withheld to satisfy tax withholding obligations in connection with the vesting of restricted stock units on March 20, 2026, which restricted stock was granted on March 20, 2024. Includes (i) 18,000 shares of restricted stock units that vest in three substantially equal installments on each of March 3, 2027, March 3, 2028 and March 3, 2029, (ii) 12,834 shares of restricted stock units that vest in two substantially equal installments on each of March 17, 2027 and March 17, 2028, and (iii) 5,834 shares of restricted stock units that vest on March 20, 2027, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date. /s/ Creighton K. Early, Attorney-in-fact for Michael A. Bieber 2026-03-23