By FOCUS, A Leonine Business
Colorado and Washington have become the first states to adopt “mini-HSR” laws, state-level versions of the federal Hart-Scott-Rodino Antitrust Improvements Act of 1976 (HSR). The federal HSR Act was a set of amendments to the Clayton Antitrust Act, the 1914 law aimed at preventing practices such as unlawful tying arrangements, anticompetitive mergers and acquisitions and interlocking directorates. The HSR amendments require companies to notify the Federal Trade Commission, the Antitrust Division of the Department of Justice, before completing certain mergers or acquisitions. It also sets waiting periods and imposes filing fees. The new laws in Colorado and Washington require certain companies that file premerger notifications with federal agencies to also file the same information with the state’s attorney general.
Colorado SB 126 was signed into law by Democratic Gov. Jared Polis on June 4. Effective August 5, it requires entities with substantial business activity in Colorado to electronically file HSR premerger notifications with the state attorney general. The law includes confidentiality protections, authorizes information sharing with other states that have similar laws and allows for civil penalties for noncompliance. Washington SB 5122/Chapter 7, which was signed into law by Democratic Gov. Bob Ferguson on April 4 and went into effect on July 27, contains similar provisions. It requires qualifying entities to file HSR forms electronically with the state attorney general, provides confidentiality safeguards, permits limited information sharing with government agencies and enforces compliance through civil penalties.
While many states have long required premerger notifications for healthcare-specific mergers, Colorado and Washington’s new laws apply across all industries. Both states modeled their statutes on the Uniform Antitrust Pre-Merger Notification Act (UAPNA), developed by the Uniform Law Commission to provide a framework for states to implement similar requirements. Under the model, companies meeting certain thresholds must submit the same premerger notification (commonly called the HSR form) that they file with federal agencies to state authorities.
California, Hawaii, Nevada, Utah, West Virginia and the District of Columbia introduced similar UAPNA-inspired legislation in 2025. While the bills in Nevada, Utah and West Virginia have died, legislation in California, Hawaii and the District of Columbia are still being considered or carrying over to 2026. New York’s SB 335, the Twenty-First Century Antitrust Act, mirrors much of the UAPNA but has looser thresholds for when filings are required. SB 335 passed the Senate and was referred to the Assembly Economic Development Committee before the legislature adjourned in June; the bill can carry over to 2026.
With these first two laws in effect, and more states considering similar measures, businesses engaged in mergers or acquisitions should be prepared for a growing wave of “Mini-HSR” laws that require state-level premerger reporting. FOCUS will continue to monitor the developments of antitrust legislation at both the state and federal levels.