ObjectivesTo evaluate how often beta-blockers were started after acute myocardial infarction (AMI) in nursing home (NH) residents who previously did not use these drugs and to evaluate which factors were associated with post-AMI use of beta-blockers. DesignRetrospective cohort using linked national Minimum Data Set assessments; Online Survey, Certification and Reporting records; and Medicare claims. SettingU.S. NHs. ParticipantsNational cohort of 15,720 residents aged 65 and older who were hospitalized for AMI between May 2007 and March 2010, had not taken beta-blockers for at least 4 months before their AMI, and survived 14 days or longer after NH readmission. MeasurementsThe outcome was beta-blocker initiation within 30 days of NH readmission. ResultsFifty-seven percent (n = 8,953) of residents initiated a beta-blocker after AMI. After covariate adjustment, use of beta-blockers was less in older residents (ranging from odds ratio (OR) = 0.89, 95% confidence interval (CI) = 0.79-1.00 for aged 75-84 to OR = 0.65, 95% CI = 0.54-0.79 for 95 vs 65-74) and less in residents with higher levels of functional impairment (dependent or totally dependent vs independent to limited assistance: OR = 0.84, 95% CI = 0.75-0.94) and medication use (15 vs 10 medications: OR = 0.89, 95% CI = 0.80-0.99). A wide variety of resident and NH characteristics were not associated with beta-blocker use, including sex, cognitive function, comorbidity burden, and NH ownership. ConclusionAlmost half of older NH residents in the United States do not initiate a beta-blocker after AMI. The absence of observed factors that strongly predict beta-blocker use may indicate a lack of consensus on how to manage older NH residents, suggesting the need to develop and disseminate thoughtful practice standards.