OBJECTIVES To describe Medicare beneficiaries’ transitions through home health care within the context of other acute and post-acute services, and to examine agreement between administrative claims and Outcome and Assessment Information Set (OASIS) measures of health services use. DATA SOURCES The 2004 Chronic Condition Data Warehouse, including the Medicare 5% standard analytic file and OASIS. Study participants were 66,510 Medicare beneficiaries with a home health start of care assessment between January 15, 2004 and July 15, 2004 who were discharged before December 1, 2004. RESULTS Home health patients frequently incurred acute and post-acute services during the 14 days preceding admission and the 30 days after discharge, predominantly in acute hospitals. Substantial differences were observed in beneficiaries’ health and functioning across living arrangements; patients living alone were less medically complex, less disabled, and received less assistance than those living with others. Agreement between OASIS and administrative claims was uniformly low with regard to inpatient hospital, inpatient rehabilitation, and skilled nursing facility use in the 14 days preceding the home health start of care. Agreement between OASIS and administrative claims was uneven for the period after discharge from home health care; it was determined to be near perfect for inpatient hospital (kappa = 0.85), but was lower for inpatient rehabilitation and hospice (kappa = 0.22 and 0.10, respectively). CONCLUSIONS Findings reinforce the potential merit of patient-specific rather than setting-specific measures of quality, but underscore practical challenges to constructing measures that span data sources and episodes of care.