If CHIRA is enacted, the Department of Justice and Federal Trade Commission would have expanded authority to regulate the business of health insurance. Arrangements between insurers to share data for the purpose of developing premiums that previously were immune from federal scrutiny may be subject to the rule of reason and a weighing of the procompetitive benefits and anticompetitive effects of the arrangements, to the extent those arrangements go beyond the remaining protections for compilation of historical loss data, determination of loss development factors, and performance of actuarial services. In addition, health insurers would be subject to suits by private plaintiffs brought under the federal antitrust laws that may previously have been subject to dismissal under the McCarran-Ferguson Act.