OBJECTIVE: To estimate the effect of independent practice association (IPA) model HMOs and the Kaiser Foundation Health Plan's group model on inpatient utilization of Medicare beneficiaries in the last 2 years of life, compared with traditional fee-for-service (FFS) coverage. STUDY DESIGN: Data from the Centers for Medicare & Medicaid Services were linked to inpatient discharge data from the California Office of Statewide Health Planning and Development for 1991-2001. A sample of aged Medicare beneficiaries who died between January 1998 and June 2001 and were continuously enrolled during the 2 years before death in (1) FFS (n = 234,498), (2) an IPA (n = 109,577), or (3) Kaiser (n = 29,434) were selected. METHODS: The probability of at least 1 hospitalization, number of inpatient days given at least 1 hospitalization, and total inpatient days per year in the last 2 years of life were estimated for each subgroup. A 2-part regression model, which adjusted for age, sex, Medicaid status, race, ethnicity, and chronic condition associated with the last hospitalization, was applied to determine the HMO-FFS difference in inpatient utilization during the last 2 years of life. RESULTS: During their last 2 years of life, decedents in IPAs and Kaiser used approximately 34% and 51% fewer inpatient days, respectively, than decedents in FFS. CONCLUSIONS: Medicare beneficiaries who died while enrolled in an HMO, particularly Kaiser, had many fewer hospital days during the 2 years before death than beneficiaries who died with FFS coverage.