Favorable selection in the Medicare+Choice program: New evidence

Historically, studying the Medicare managed care favorable-selection issue has been difficult because direct data on managed care enrollees have been unavailable. In this study, we analyzed the first year of Balanced Budget Act (BBA)-mandated inpatient encounter data. Based on this comparison of actual managed care and fee-for- service (FFS) beneficiaries, it appears that there are significant differences between these populations. The most striking differences are found in the comparison of average risk factors, indicating a clear bias in the managed care populations toward beneficiaries predicted to be less costly.