In this article, case-mix-adjusted outcomes of home health care are found to be superior for Medicare fee-for-service (FFS) patients relative to Medicare health maintenance organization (HMO) patients. The superior outcomes for FFS patients were accompanied by higher utilization and cost of home health services, suggesting a volume-outcome (or dose-response) relationship that was further substantiated by within-HMO and within-FFS analyses. The findings suggest that greater attention should be paid to both outcome-based quality assurance and managed care practices that may be overly restrictive in terms of the use of home health services.