Washington Introduces State-Level Merger Notification Rules

States’ merger review and enforcement initiatives continue to expand as Washington adopts the nation’s first “mini-HSR” rule.

On April 4, 2025, the State of Washington passed the Antitrust Premerger Notification Act (APNA). Under this law, starting July 27, 2025, any party to an M&A transaction that triggers a federal Hart-ScottRodino Act (HSR Act) filing with the US Federal Trade Commission (FTC) and US Department of Justice (DOJ) must also submit a copy of the HSR filing to the Washington Attorney General (WA OAG) if the filing party (1) maintains a principal place of business in Washington, (2) generates in-state net revenues over certain thresholds described below, or (3) provides healthcare in the state.