Upcoding: Evidence from Medicare on Squishy Risk Adjustment

• 成果类型: Article
• 署名作者: Geruso, Michael; Layton, Timothy
• 署名单位: University of Texas System; University of Texas Austin; National Bureau of Economic Research; Harvard University; Harvard Medical School
• 刊物名称: JOURNAL OF POLITICAL ECONOMY
• ISSN/ISSBN: 0022-3808
• DOI: 10.1086/704756
• 发表日期: 2020
• 页码: 984-1026
• 关键词: insurance markets; health-insurance; plan choice; part d; advantage; selection; welfare; incentives; benefits; PREMIUMS

摘要

In most US health insurance markets, plans face strong incentives to upcode the patient diagnoses they report to the regulator, as these affect the risk-adjusted payments that plans receive. We show that enrollees in private Medicare plans generate 6%-16% higher diagnosis-based risk scores than they would under fee-for-service Medicare, where diagnoses do not affect most provider payments. Our estimates imply that upcoding generates billions in excess public spending and significant distortions to firm and consumer behavior. We show that coding intensity increases with vertical integration, suggesting a principal-agent problem faced by insurers, who desire more intense coding from the providers with whom they contract.