This brief from the research team led by SHARE grantee Andrew Coburn, Ph.D., Professor and Chair of Health Policy and Management at the Muskie School of Public Service at the University of Southern Maine, examines how and to what extent states allow health plans to vary premiums by geographic rating area, using insurance data from selected states to assess the direction and magnitude of variations in rural and urban geographic rating factors.  The authors also discuss strategies that federal and state policymakers might use to help ensure that premium variations based on geography are justified.