Since 1978, federal antitrust law explicitly authorizes state attorneys general to appear either singly or in conjunction with other states in federal court on a broad array of antitrust issues. When coupled with state law, most attorneys general have the jurisdiction to block mergers or seek direct or indirect damages on behalf of governmental agencies and citizens.

The legal ability to join together in a single federal court has led to many multistate antitrust actions where attorneys general are often joined by the U.S. Department of Justice, the Federal Trade Commission and by private litigants including particular companies and class counsel. These efforts are nonetheless limited by resources, unpredictable impacts on in-state businesses and by prudence. Virtually all state antitrust cases settle short of trial.

Single state antitrust actions are increasingly rare and usually brought by the minority of states with larger antitrust divisions.

Even before the passage of the Affordable Care Act (“ACA”) that contains antitrust provisions (Accountable Care Organizations “ACO”), attorneys general have focused their single state antitrust attention to health related issues.