Medicare's Hospital Readmission Reduction Program (HRRP) penalizes hospitals with elevated 30-day readmission rates for acute myocardial infarction (AMI), heart failure (HF), or pneumonia. To reduce readmissions, hospitals may have increased referrals to skilled nursing facilities (SNFs) and home health care.Outcomes included 30-day postdischarge utilization of SNF and home health care, including any use as well as days of use. Subjects included Medicare fee-for-service beneficiaries aged 65 years and older who were admitted with AMI, HF, or pneumonia to hospitals subject to the HRRP. Using an interrupted time-series analysis, we compared utilization rates observed after the announcement of the HRRP (April 2010 through September 2012) and after the imposition of penalties (October 2012 through September 2014) with projected utilization rates that accounted for pre-HRRP trends (January 2008 through March 2010). Models included patient characteristics and hospital fixed effects.For AMI and HF, utilization of SNF and home health care remained stable overall. For pneumonia, observed utilization of any SNF care increased modestly (1.0%, P<0.001 during anticipation; 2.4%, P<0.001 after penalties) and observed utilization of any home health care services declined modestly (-0.5%, P=0.008 after announcement; -0.7%, P=0.045 after penalties) relative to projections. Beneficiaries with AMI and pneumonia treated at penalized hospitals had higher rates of being in the community 30 days postdischarge.Hospitals might be shifting to more intensive postacute care to avoid readmissions among seniors with pneumonia. At the same time, penalized hospitals' efforts to prevent readmissions may be keeping higher proportions of their patients in the community.