AB 339 Explainer: Providing Notice to Bargaining Units AB 339 Explainer: Providing Notice to Bargaining Units AB 339 Makes a Significant Impact on Public Agency Contracting and Labor Relations Here's what you need to know: AB 339, enacted on October 13, 2025, introduces Government Code Section 3504 1, requiring public entities to provide written notice to recognized employee organizations no less than 45 days before issuing requests for proposals