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Amended and Restated 2008 Performance Incentive Plan, which vested in three equal installments on each of March 8, 2018, March 8, 2019, and March 8, 2020."}],"balance_after":0,"derivative":{"exercise_price":28.19,"exercise_date":"2018-03-08","expiration_date":"2027-03-08","underlying":"Common Stock","underlying_shares":16667},"source":{"system":"sec-edgar","filing":"0001270606-26-000017","document":"form4-05152026_100506.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":8,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000017/form4-05152026_100506.xml","form_type":"4"}},{"id":776880,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2026-05-15T22:08:15.000Z","date":"2026-05-14","kind":"exercise","planned":false,"acquired":false,"shares":40009,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F6","text":"Stock options granted under the Willdan Group, Inc. 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These shares were sold in multiple transactions at prices ranging from $92.50 to $93.41, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"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."}],"balance_after":249801,"source":{"system":"sec-edgar","filing":"0001270606-26-000017","document":"form4-05152026_100506.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000017/form4-05152026_100506.xml","form_type":"4"}},{"id":776877,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2026-05-15T22:08:15.000Z","date":"2026-05-14","kind":"sale","planned":false,"acquired":false,"shares":23015,"price":91.95,"value":2116229.25,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $91.50 to $92.49, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"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."}],"balance_after":257757,"source":{"system":"sec-edgar","filing":"0001270606-26-000017","document":"form4-05152026_100506.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000017/form4-05152026_100506.xml","form_type":"4"}},{"id":776876,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2026-05-15T22:08:15.000Z","date":"2026-05-14","kind":"sale","planned":false,"acquired":false,"shares":25429,"price":90.88,"value":2310987.52,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $90.50 to $91.46, 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 ranges set forth in this footnote (2), footnote (3), footnote (4), and footnote (5)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"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."}],"balance_after":280772,"source":{"system":"sec-edgar","filing":"0001270606-26-000017","document":"form4-05152026_100506.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000017/form4-05152026_100506.xml","form_type":"4"}},{"id":776875,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2026-05-15T22:08:15.000Z","date":"2026-05-14","kind":"exercise","planned":false,"acquired":true,"shares":16667,"price":28.19,"value":469842.73,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"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."}],"balance_after":306201,"source":{"system":"sec-edgar","filing":"0001270606-26-000017","document":"form4-05152026_100506.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000017/form4-05152026_100506.xml","form_type":"4"}},{"id":776874,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2026-05-15T22:08:15.000Z","date":"2026-05-14","kind":"exercise","planned":false,"acquired":true,"shares":40009,"price":16.27,"value":650946.43,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"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."}],"balance_after":289534,"source":{"system":"sec-edgar","filing":"0001270606-26-000017","document":"form4-05152026_100506.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000017/form4-05152026_100506.xml","form_type":"4"}},{"id":778845,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2026-05-14T21:56:02.000Z","date":"2026-05-13","kind":"exercise","planned":false,"acquired":false,"shares":9991,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"Stock options granted under the Willdan Group, Inc. 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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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"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 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The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee effective on March 16, 2026, resulting in the immediate vesting of the restricted stock units as to 17,326 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"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) 19,250 shares of restricted stock units that vest in three substantially equal installments on each of March 17, 2026, March 17, 2027 and March 17, 2028, and (iii) 11,667 shares of restricted stock units that vest in two substantially equal installments on each of March 20, 2026 and March 20, 2027, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":252321,"source":{"system":"sec-edgar","filing":"0001270606-26-000008","document":"form4-03172026_090312.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000008/form4-03172026_090312.xml","form_type":"4"}},{"id":845816,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2026-03-12T21:33:17.000Z","date":"2026-03-11","kind":"tax_withholding","planned":false,"acquired":false,"shares":7697,"price":83.98,"value":646394.06,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents shares of the Issuer's Common Stock withheld to satisfy tax withholding obligations in connection with the vesting of the performance-based restricted stock units referenced in footnote (1)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"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) 19,250 shares of restricted stock units that vest in three substantially equal installments on each of March 17, 2026, March 17, 2027 and March 17, 2028, and (iii) 11,667 shares of restricted stock units that vest in two substantially equal installments on each of March 20, 2026 and March 20, 2027, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":234995,"source":{"system":"sec-edgar","filing":"0001270606-26-000006","document":"form4-03122026_090314.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000006/form4-03122026_090314.xml","form_type":"4"}},{"id":845815,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2026-03-12T21:33:17.000Z","date":"2026-03-11","kind":"grant","planned":false,"acquired":true,"shares":18810,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on March 7, 2023. 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(iii) 11,667 shares of restricted stock units that vest in two substantially equal installments on each of March 20, 2026 and March 20, 2027 and (iv) 4,434 shares of restricted stock that vest on March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 154 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on December 31, 2025."}],"balance_after":225696,"source":{"system":"sec-edgar","filing":"0001270606-26-000002","document":"form4-03052026_100346.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000127060626000002/form4-03052026_100346.xml","form_type":"4"}},{"id":1060104,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, 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These shares were sold in multiple transactions at prices ranging from $48.10 to $48.30, 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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 19,250 shares of restricted stock units that vest in three substantially equal installments on each of March 17, 2026, March 17, 2027 and March 17, 2028, (ii) 11,667 shares of restricted stock units that vest in two substantially equal installments on each of March 20, 2026 and March 20, 2027 and (iii) 4,434 shares of restricted stock that vest on March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting 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The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee effective on  March 11, 2025, resulting in the immediate vesting of the restricted stock units as to 11,970 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 4,434 shares of restricted stock that vest on March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":183549,"source":{"system":"sec-edgar","filing":"0001415889-25-007903","document":"form4-03122025_100354.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588925007903/form4-03122025_100354.xml","form_type":"4"}},{"id":1211908,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2025-03-11T21:38:54.000Z","date":"2025-03-07","kind":"tax_withholding","planned":false,"acquired":false,"shares":2429,"price":41.8,"value":101532.2,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock withheld to satisfy tax withholding obligations in connection with the vesting of restricted stock on March 7, 2025, which restricted stock was granted on March 7, 2023."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 354 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on December 31, 2024."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 4,434 shares of restricted stock that vest on March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":171579,"source":{"system":"sec-edgar","filing":"0001415889-25-007691","document":"form4-03112025_090351.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588925007691/form4-03112025_090351.xml","form_type":"4"}},{"id":1368647,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2024-11-12T22:30:40.000Z","date":"2024-11-11","kind":"exercise","planned":false,"acquired":false,"shares":10868,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"Stock options granted under the Willdan Group, Inc. 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The performance conditions applicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on July 30, 2024, resulting in the immediate vesting of the restricted stock units as to 8,246 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":177972,"source":{"system":"sec-edgar","filing":"0001415889-24-021847","document":"form4-08212024_090804.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924021847/form4-08212024_090804.xml","form_type":"4"}},{"id":1433500,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2024-08-14T22:08:40.000Z","date":"2024-08-12","kind":"exercise","planned":false,"acquired":false,"shares":750,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"Stock options granted under the Willdan Group, Inc. 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These shares were sold in multiple transactions at prices ranging from $36.35 to $36.39, 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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":169726,"source":{"system":"sec-edgar","filing":"0001415889-24-021105","document":"form4-08122024_090804.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924021105/form4-08122024_090804.xml","form_type":"4"}},{"id":1435869,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-08-12T21:33:07.000Z","date":"2024-08-09","kind":"exercise","planned":false,"acquired":true,"shares":9209,"price":13.49,"value":124229.41,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":178935,"source":{"system":"sec-edgar","filing":"0001415889-24-021105","document":"form4-08122024_090804.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924021105/form4-08122024_090804.xml","form_type":"4"}},{"id":1435868,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-08-12T21:33:07.000Z","date":"2024-08-08","kind":"sale","planned":false,"acquired":false,"shares":10273,"price":36.43,"value":374245.39,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. 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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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":169726,"source":{"system":"sec-edgar","filing":"0001415889-24-021105","document":"form4-08122024_090804.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924021105/form4-08122024_090804.xml","form_type":"4"}},{"id":1435867,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-08-12T21:33:07.000Z","date":"2024-08-08","kind":"exercise","planned":false,"acquired":true,"shares":10273,"price":13.49,"value":138582.77,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":179999,"source":{"system":"sec-edgar","filing":"0001415889-24-021105","document":"form4-08122024_090804.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924021105/form4-08122024_090804.xml","form_type":"4"}},{"id":1437762,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2024-08-08T21:36:07.000Z","date":"2024-08-07","kind":"exercise","planned":false,"acquired":false,"shares":10346,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"Stock options granted under the Willdan Group, Inc. 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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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 683 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2024."}],"balance_after":169726,"source":{"system":"sec-edgar","filing":"0001415889-24-020997","document":"form4-08082024_090803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924020997/form4-08082024_090803.xml","form_type":"4"}},{"id":1437759,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-08-08T21:36:07.000Z","date":"2024-08-07","kind":"exercise","planned":false,"acquired":true,"shares":10346,"price":13.49,"value":139567.54,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 683 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2024."}],"balance_after":180072,"source":{"system":"sec-edgar","filing":"0001415889-24-020997","document":"form4-08082024_090803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924020997/form4-08082024_090803.xml","form_type":"4"}},{"id":1437758,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-08-08T21:36:07.000Z","date":"2024-08-06","kind":"sale","planned":false,"acquired":false,"shares":12000,"price":36.58,"value":438960.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is the weighted average price. 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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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 683 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2024."}],"balance_after":169726,"source":{"system":"sec-edgar","filing":"0001415889-24-020997","document":"form4-08082024_090803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924020997/form4-08082024_090803.xml","form_type":"4"}},{"id":1437757,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-08-08T21:36:07.000Z","date":"2024-08-06","kind":"exercise","planned":false,"acquired":true,"shares":12000,"price":13.49,"value":161880.0,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 683 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2024."}],"balance_after":181726,"source":{"system":"sec-edgar","filing":"0001415889-24-020997","document":"form4-08082024_090803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924020997/form4-08082024_090803.xml","form_type":"4"}},{"id":1478803,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2024-06-14T21:31:57.000Z","date":"2024-06-13","kind":"exercise","planned":false,"acquired":false,"shares":6000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"Stock options granted under the Willdan Group, Inc. 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These shares were sold in multiple transactions at prices ranging from $30.30 to $30.44, 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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":169043,"source":{"system":"sec-edgar","filing":"0001415889-24-016978","document":"form4-06142024_090653.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016978/form4-06142024_090653.xml","form_type":"4"}},{"id":1478801,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-06-14T21:31:57.000Z","date":"2024-06-13","kind":"exercise","planned":false,"acquired":true,"shares":6000,"price":13.49,"value":80940.0,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":173503,"source":{"system":"sec-edgar","filing":"0001415889-24-016978","document":"form4-06142024_090653.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016978/form4-06142024_090653.xml","form_type":"4"}},{"id":1480412,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2024-06-13T22:13:06.000Z","date":"2024-06-12","kind":"exercise","planned":false,"acquired":false,"shares":6000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"Stock options granted under the Willdan Group, Inc. 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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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":167503,"source":{"system":"sec-edgar","filing":"0001415889-24-016725","document":"form4-06132024_100603.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016725/form4-06132024_100603.xml","form_type":"4"}},{"id":1480409,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-06-13T22:13:06.000Z","date":"2024-06-12","kind":"exercise","planned":false,"acquired":true,"shares":6000,"price":13.49,"value":80940.0,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":171897,"source":{"system":"sec-edgar","filing":"0001415889-24-016725","document":"form4-06132024_100603.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016725/form4-06132024_100603.xml","form_type":"4"}},{"id":1480408,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-06-13T22:13:06.000Z","date":"2024-06-11","kind":"sale","planned":false,"acquired":false,"shares":4464,"price":30.25,"value":135036.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. 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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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":165897,"source":{"system":"sec-edgar","filing":"0001415889-24-016725","document":"form4-06132024_100603.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016725/form4-06132024_100603.xml","form_type":"4"}},{"id":1480407,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-06-13T22:13:06.000Z","date":"2024-06-11","kind":"exercise","planned":false,"acquired":true,"shares":6000,"price":13.49,"value":80940.0,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":170361,"source":{"system":"sec-edgar","filing":"0001415889-24-016725","document":"form4-06132024_100603.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016725/form4-06132024_100603.xml","form_type":"4"}},{"id":1481898,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Stock Options (Right to Buy)","published_at":"2024-06-12T21:50:16.000Z","date":"2024-06-10","kind":"exercise","planned":false,"acquired":false,"shares":4514,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"Stock options granted under the Willdan Group, Inc. 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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 ranges set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":164361,"source":{"system":"sec-edgar","filing":"0001415889-24-016535","document":"form4-06122024_090613.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016535/form4-06122024_090613.xml","form_type":"4"}},{"id":1481896,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-06-12T21:50:16.000Z","date":"2024-06-10","kind":"exercise","planned":false,"acquired":true,"shares":4514,"price":13.49,"value":60893.86,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":167694,"source":{"system":"sec-edgar","filing":"0001415889-24-016535","document":"form4-06122024_090613.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924016535/form4-06122024_090613.xml","form_type":"4"}},{"id":1563223,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-03-22T21:33:15.000Z","date":"2024-03-20","kind":"tax_withholding","planned":false,"acquired":false,"shares":5303,"price":27.55,"value":146097.65,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F4","text":"Represents shares of the Issuer's Common Stock withheld to satisfy tax withholding obligations in connection with the vesting of the performance-based restricted stock units referenced in footnote (3)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes (i) 17,500 shares of restricted stock units that vest in three substantially equal installments on each of March 20, 2025, March 20, 2026 and March 20, 2027 and (ii) 8,867 shares of restricted stock that vest in two substantially equal installments on each of March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":163180,"source":{"system":"sec-edgar","filing":"0001415889-24-009000","document":"form4-03222024_090308.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588924009000/form4-03222024_090308.xml","form_type":"4"}},{"id":1563222,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT AND CEO"}}],"security":"Common Stock","published_at":"2024-03-22T21:33:15.000Z","date":"2024-03-20","kind":"grant","planned":false,"acquired":true,"shares":11970,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on March 7, 2023. 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These shares were sold in multiple transactions at prices ranging from $24.68 to $24.75, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":140676,"source":{"system":"sec-edgar","filing":"0001415889-23-012722","document":"form4-08282023_100808.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923012722/form4-08282023_100808.xml","form_type":"4"}},{"id":1795120,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-08-28T22:17:16.000Z","date":"2023-08-24","kind":"sale","planned":false,"acquired":false,"shares":964,"price":24.34,"value":23463.76,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of the performance-based restricted stock units on August 21, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $23.67 to $24.65, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, 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 ranges set forth in this footnote (2) and footnote (4)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":140738,"source":{"system":"sec-edgar","filing":"0001415889-23-012722","document":"form4-08282023_100808.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923012722/form4-08282023_100808.xml","form_type":"4"}},{"id":1797546,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-08-24T21:42:34.000Z","date":"2023-08-23","kind":"sale","planned":false,"acquired":false,"shares":499,"price":23.81,"value":11881.19,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting\nof the performance-based restricted stock units on August 21, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $23.65 to $24.15, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":141702,"source":{"system":"sec-edgar","filing":"0001415889-23-012618","document":"form4-08242023_090826.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923012618/form4-08242023_090826.xml","form_type":"4"}},{"id":1797545,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-08-24T21:42:34.000Z","date":"2023-08-23","kind":"sale","planned":false,"acquired":false,"shares":671,"price":23.29,"value":15627.59,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting\nof the performance-based restricted stock units on August 21, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $22.65 to $23.64, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":142201,"source":{"system":"sec-edgar","filing":"0001415889-23-012618","document":"form4-08242023_090826.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923012618/form4-08242023_090826.xml","form_type":"4"}},{"id":1797544,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-08-24T21:42:34.000Z","date":"2023-08-22","kind":"sale","planned":false,"acquired":false,"shares":1216,"price":22.82,"value":27749.12,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting\nof the performance-based restricted stock units on August 21, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $22.60 to $23.09, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, 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 ranges set forth in this footnote (2), footnote (4) and footnote (5)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":142872,"source":{"system":"sec-edgar","filing":"0001415889-23-012618","document":"form4-08242023_090826.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923012618/form4-08242023_090826.xml","form_type":"4"}},{"id":1799548,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-08-22T22:15:09.000Z","date":"2023-08-21","kind":"grant","planned":false,"acquired":true,"shares":8246,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents performance-based restricted stock units previously granted to the Reporting Person by the Issuer on August 2, 2022. The performance conditions\napplicable to the award were determined to have been satisfied by the Issuer's Compensation Committee on August 21, 2023, resulting in the immediate vesting of the restricted stock units as to 8,246 shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 823 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on June 30, 2023."}],"balance_after":144088,"source":{"system":"sec-edgar","filing":"0001415889-23-012518","document":"form4-08222023_100803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923012518/form4-08222023_100803.xml","form_type":"4"}},{"id":1953925,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-03-15T00:14:19.000Z","date":"2023-03-13","kind":"sale","acquired":false,"shares":1094,"price":16.77,"value":18346.38,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of restricted stock on March 8, 2023, which restricted stock was granted on March 8, 2022."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $16.54 to $17.04, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":135019,"source":{"system":"sec-edgar","filing":"0001415889-23-004911","document":"form4-03152023_120310.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923004911/form4-03152023_120310.xml","form_type":"4"}},{"id":1953924,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-03-15T00:14:19.000Z","date":"2023-03-13","kind":"sale","acquired":false,"shares":1758,"price":16.15,"value":28391.7,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of restricted stock on March 8, 2023, which restricted stock was granted on March 8, 2022."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $15.53 to $16.52, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, 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 ranges set forth in this footnote (2) and footnote (4)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":136113,"source":{"system":"sec-edgar","filing":"0001415889-23-004911","document":"form4-03152023_120310.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923004911/form4-03152023_120310.xml","form_type":"4"}},{"id":1956567,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-03-13T22:54:12.000Z","date":"2023-03-10","kind":"sale","acquired":false,"shares":257,"price":16.96,"value":4358.72,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of restricted stock on March 8, 2023, which restricted stock was granted on March 8, 2022."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $16.60 to $17.00, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":137871,"source":{"system":"sec-edgar","filing":"0001415889-23-004815","document":"form4-03132023_100305.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923004815/form4-03132023_100305.xml","form_type":"4"}},{"id":1956566,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-03-13T22:54:12.000Z","date":"2023-03-10","kind":"sale","acquired":false,"shares":1159,"price":15.78,"value":18289.02,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of restricted stock on March 8, 2023, which restricted stock was granted on March 8, 2022."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $15.56 to $16.53, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":138128,"source":{"system":"sec-edgar","filing":"0001415889-23-004815","document":"form4-03132023_100305.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923004815/form4-03132023_100305.xml","form_type":"4"}},{"id":1956565,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-03-13T22:54:12.000Z","date":"2023-03-10","kind":"sale","acquired":false,"shares":1306,"price":15.21,"value":19864.26,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of restricted stock on March 8, 2023, which restricted stock was granted on March 8, 2022."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $14.55 to $15.53, inclusive.\nThe Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full\ninformation regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2), footnote (4) and footnote (5)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":139287,"source":{"system":"sec-edgar","filing":"0001415889-23-004815","document":"form4-03132023_100305.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923004815/form4-03132023_100305.xml","form_type":"4"}},{"id":1958578,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-03-10T23:07:39.000Z","date":"2023-03-09","kind":"sale","acquired":false,"shares":2932,"price":17.03,"value":49931.96,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of the Issuer's Common Stock sold in the open market, the proceeds of which were used to pay the tax withholding obligations incurred upon the vesting of restricted stock on March 8, 2023, which restricted stock was granted on March 8, 2022."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $16.90 to $17.35, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, 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 in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 13,300 shares of restricted stock that vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":140593,"source":{"system":"sec-edgar","filing":"0001415889-23-004688","document":"form4-03102023_110331.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923004688/form4-03102023_110331.xml","form_type":"4"}},{"id":1963002,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2023-03-08T23:39:14.000Z","date":"2023-03-07","kind":"grant","acquired":true,"shares":13300,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares of restricted stock awarded to the Reporting Person by the Issuer on March 7, 2023, which vest in three substantially equal installments on each of March 7, 2024, March 7, 2025 and March 7, 2026, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 238 shares of Common Stock purchased under the Amended and Restated Willdan Group, Inc. 2006 Employee Stock Purchase Plan on December 31, 2022."}],"balance_after":143525,"source":{"system":"sec-edgar","filing":"0001415889-23-004538","document":"form4-03082023_110353.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588923004538/form4-03082023_110353.xml","form_type":"4"}},{"id":2186813,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Stock Options (Right to Buy)","published_at":"2022-08-12T22:03:54.000Z","date":"2022-08-10","kind":"exercise","acquired":true,"shares":24666,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"Stock options granted under the Willdan Group, Inc. 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These shares were sold in multiple transactions at prices ranging from $27.34 to $27.90, inclusive."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Includes 18,051 shares of restricted stock that vest in one installment on March 8, 2023, subject to the Reporting Person's continued service to the Issuer through the applicable vesting date."}],"balance_after":129987,"source":{"system":"sec-edgar","filing":"0001415889-22-008569","document":"form4-08122022_030842.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1270606/000141588922008569/form4-08122022_030842.xml","form_type":"4"}},{"id":2186811,"issuer":{"id":4758,"kind":"organization","name":"Willdan Group, Inc.","symbol":"WLDN"},"owners":[{"id":46860,"kind":"person","name":"BIEBER MICHAEL A","position":1,"cik":"0001270606","reported_name":"BIEBER MICHAEL A","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT"}}],"security":"Common Stock","published_at":"2022-08-12T22:03:54.000Z","date":"2022-08-10","kind":"sale","acquired":false,"shares":24666,"price":27.66,"value":682261.56,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $27.34 to $28.03, inclusive. 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