Introduction: Advances in the acute treatment of myocardial infarction (AMI) substantially reduced in-hospital mortality, but the post-discharge prognosis is still unacceptable. The Managed Care in Acute Myocardial Infarction (MC-AMI) is a program of Poland’s National Health Fund that aims at comprehensive post-AMI care to improve long-term prognosis. The aim of the study was to assess the effect of MC-AMI on all-cause mortality in one-year follow-up. Methods: MC-AMI includes acute MI treatment, complex revascularization, cardiac rehabilitation (CR), scheduled one-year outpatient follow-up, and prevention of sudden cardiac death. In this retrospective observational study performed in a province of Silesia, Poland, we analyzed 3893 MC-AMI participants, and compared them to 6946 patients in the control group. After propensity score matching, we compared two groups of 3551 subjects each. To assess the effect of MC-AMI and other variables on mortality, we preformed a Cox regression. Results: MC-AMI was related with mortality reduction by 38% in a 12-month observation period and the effect persisted even after. Multivariable Cox regression analysis revealed MC-AMI participation to be inversely associated with 1-year mortality (HR 0.52, 95%CI 0.42–0.65, p < 0.001). Besides that, older age (HR 1.47/10 y), ST-elevation AMI (HR 1.41), heart failure (HR 2.08), diabetes (HR 1.52), and dialysis (HR 2.38) were significantly associated with the primary endpoint. Among MC-AMI components, cardiac rehabilitation (HR 0.34) and strict outpatient care (HR 0.42) are the crucial factors affecting mortality reduction. Conclusions: Participation in MC-AMI reduced 1-year mortality by 38% and the effect persisted after the program had been completed.