BACKGROUND: Although the benefits of statins accrue over time, treatment discontinuation is common. Examining the patterns of statin discontinuation, reinitiation, and persistence after reinitiation among Medicare beneficiaries after hospital discharge for a myocardial infarction may help increase statin use in high-risk patients. METHODS AND RESULTS: Medicare beneficiaries with a statin fill claim within 30 days after hospital discharge for myocardial infarction in 2007 to 2012 (n=158 795) were followed for 182 days post-discharge to identify discontinuation, defined as 60 continuous days without statins available. Reinitiation, defined by a statin fill, was identified in the 365 days post-discontinuation. High persistence was defined as proportion of days covered ≥80% with ≥1 day of statin supply 182 days after reinitiation. Follow-up ended on December 31, 2014. In the 182 days after myocardial infarction hospital discharge, 15.4% of beneficiaries discontinued statins. Of this group, 53.7% reinitiated statins. On reinitiation, 27.1% changed statin type, 6.9% up-titrated intensity, 14.4% down-titrated intensity, and 66.0% had the same statin and intensity. In the 182 days after reinitiation, 45.8% had high persistence. Moderate- and high- versus low-intensity statins were associated with a lower risk for statin discontinuation (moderate intensity: relative risk [RR], 0.93; 95% confidence interval [CI], 0.89-0.96; high-intensity: RR, 0.95; 95% CI, 0.91-0.99). High persistence was less common after reinitiating high- versus low-intensity statins (RR, 0.80; 95% CI, 0.75-0.86), but no association was present for those reinitiating a moderate- versus low-intensity statin (RR, 0.95; 95% CI, 0.90-1.01). Down-titrating versus reinitiating the same statin intensity (RR, 1.10; 95% CI, 1.05-1.16) and reinitiating a different versus the same statin (RR, 1.10; 95% CI, 1.06-1.14) were associated with high persistence after treatment reinitiation. CONCLUSIONS: Although many people who discontinue a statin reinitiate treatment, statin persistence after reinitiation was low. Reinitiating therapy with moderate-intensity statins, down-titration, and using a different statin may promote persistence.