Washington will be the first state to require companies to file a premerger notification to the state Attorney General’s Office at the same time they file the notification to the federal government.

Under the Hart-Scott-Rodino (HSR) Act, companies are required to file a premerger notification to the federal government when they plan acquisitions or mergers of a certain size. 

Under the new state law, SB 5122, passed earlier this year, companies based in Washington or which do a certain amount of relevant sales in the state will be required to submit the same notification to the attorney general at the same time, effective July 27.

There is no fee for the state notification filing, and it will give the state more lead time to analyze mergers for possible anticompetitive effects. 

The Office of the Attorney General’s Antitrust Division is responsible for enforcing federal and state antitrust laws. Mergers are evaluated by division attorneys and professional staff to determine if they are likely to create or enhance market power. 

The premerger notification requirement applies to companies or individuals that:

• Have a principal place of business in Washington.
• Directly or indirectly have annual net sales in the state of goods or services involved in the proposed merger of at least 20% of the HSR filing threshold. In 2025, 20% of the HSR filing threshold is $25.28 million.
• Are health care providers. 

Washington has required premerger notification for acquisitions or mergers involving hospitals, hospital systems and provider organizations since 2019. That law remains in effect.