The researchers assessed the impact of state-level rate review regulations on health insurance premiums. Focusing on the individual and small group markets during the period 2001-2010, the researchers examined two forms of rate regulation: “file and use authority,” under which insurers can apply a rate increase without state approval and “prior-approval authority,” which requires insurers to get approval by the state or wait until a deeming period has passed before applying a premium increase. The goal of this project was to inform state and federal policymakers on whether rate review regulation moderates health insurance premium increases, making insurance more affordable for families and small employers.