Risk-type concentration and efficiency incentives: a challenge for the risk adjustment formula

Abstract

An important goal of risk-adjusted capitation payments (RACPs) to competitive community-rated health plans-that may differ in coverage and/or the organisation of delivering care-is to reduce incentives for risk selection while maintaining incentives for efficiency. In most schemes, RACPs are simply based on the average observed costs in risk groups (in a prior year). We show that under this procedure, incentives for efficiency will not always be maintained: when identical risk types are concentrated in the same health plans-due to selection, specialisation or just coincidence-cost savings can be captured by the RACPs and leak away from these plans.