X0306 4 2020-05-18 0 0001370450 Willdan Group, Inc. WLDN 0001640436 Shahidehpour Mohammad 2401 EAST KATELLA AVENUE SUITE 300 ANAHEIM CA 92806 1 0 0 0 Common Stock 2020-05-18 4 S 0 7110 22.49 D 7200 D The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $22.49 to $22.57, inclusive. The reporting person undertakes to provide to Willdan Group, Inc., any security holder of Willdan Group, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. Includes (i) 491 shares of restricted stock that vest on June 8, 2020, (ii) 1,657 shares of restricted stock that vest in two substantially equal installments on each of June 13, 2020 and June 13, 2021 and (iii) 2,168 shares of restricted stock that vest in two substantially equal installments on each of June 13, 2020 and June 13, 2021. Stacy B. McLaughlin, Attorney-in-fact for Mohammad Shahidehpour 2020-05-18