After inpatient hospitalization, many elderly patients with congestive heart failure (CHF) are discharged home and receive post-acute home care from informal (family) caregivers and formal service providers. Hospital readmission rates are high among elderly patients with CHF, and it is thought that use of informal and formal services may reduce hospital readmission during the post-acute period. Using proportional Cox regression analysis, the authors examined the independent and joint effects of post-acute informal and formal services on hospital readmission. No evidence of service impact was found. Rather, hospital readmission was associated with a longer length of CHF history and noncompliance with medication regimes. Research, policy, and practice implications are discussed.