Willdan Group, Inc.

We are providing the following disclosure in lieu of filing a Current Report on Form 8-K relating to Item 1.01 Entry into a Material Definitive Agreement and Item 3.02 Unregistered Sales of Equity Securities*:*

*Item 1.01 Entry into a Material Definitive Agreement

On May 4, 2026 (the “Burton Closing Date”), the Company, through its wholly owned subsidiary, WES, acquired all of the equity of Burton, pursuant to the terms of the Equity Purchase Agreement, dated as of May 4, 2026 (the “Burton Equity Purchase Agreement”), by and among the Company, WES, and each of the shareholders of Burton (the “Burton Shareholders”).

Pursuant to the terms of the Burton Equity Purchase Agreement, the Company agreed to pay up to $74.0 million for the purchase of all the equity of Burton, consisting of (i) $52.0 million in cash paid on the Burton Closing Date (subject to holdbacks and adjustments), (ii) $10.0 million in shares of the Company’s common stock, based on the volume weighted closing average price per share of the Company’s common stock for the twenty trading days immediately preceding the third trading day prior to the Burton Closing Date, and (iii) up to $12.0 million in cash if Burton exceeds certain financial targets during the two years after the Burton Closing Date, as more fully described below (such potential payments of up to $12.0 million being referred to as “Burton Earnout Payments” and $12.0 million in respect thereof, being referred to as the “Burton Maximum Payout”). The Company issued 131,626 shares of the Company’s common stock and the shares have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), and were issued and sold in reliance upon the exemption from registration contained in Section 4(a)(2) of the Securities Act.

The amount of the Burton Earnout Payments to be paid will be determined based on Burton’s earnings before interest, taxes, depreciation and amortization (“Burton EBITDA”). The Burton Shareholders will receive Burton Earnout Payments in each of the two years after the Burton Closing Date (the “Burton Earnout Period”) based on the amount by which Burton EBITDA exceeds certain targets. The amounts due to the Burton Shareholders as Burton Earnout Payments will in no event, individually or in the aggregate, exceed the Burton Maximum Payout. Burton Earnout Payments will be made in annual installments for each of the two years of the Burton Earnout Period. In addition, the Burton Earnout Payments will be subject to certain subordination provisions in favor of the lenders under the Company’s Amended and Restated Credit Agreement.

The Burton Equity Purchase Agreement contains customary representations and warranties regarding the Company, WES, Burton, and the Burton Shareholders, indemnification provisions, and other provisions customary for transactions of this nature.

The Company borrowed $30.0 million from its revolving credit facility and used cash on hand to fund the initial purchase price.

Burton provides comprehensive energy management and energy efficiency consulting for multi-site corporations, helping them reduce energy, water, and waste costs through utility data management and rate optimization, energy procurement and risk management, energy and water conservation/audits, and turnkey HVAC and EMS program management. Burton’s financial information will be included within the Energy segment beginning in the second quarter of fiscal year 2026 and the Company expects to finalize the purchase price allocation related to this transaction by the end of the first quarter of fiscal year 2027.

Item 3.02 Unregistered Sales of Equity Securities.

The information described in Item 1.01 above is hereby incorporated herein by reference.

The foregoing description of the Burton Equity Purchase Agreement is qualified in its entirety by reference to the full text of the Burton Equity Purchase Agreement, a copy of which is filed as Exhibit 2.2 to this Quarterly Report on Form 10-Q.