Incidence rates of acute coronary heart disease (ACHD; including myocardial infarction and angina pectoris), stroke, and heart failure (HF) were studied for their age, disability, and comorbidity patterns in the U.S. elderly population using the National Long Term Care Survey (NLTCS) data linked to Medicare records for 1991–2005. Incidence rates increased with age with a decrease in the oldest old (stroke and HF) or were stable at all ages (ACHD). For all diseases, incidence rates were lower among institutionalized individuals and higher in individuals with higher comorbidity indices. The results could be used for understanding currently debated effects of biomedical research, screening, and therapeutic innovations on changes in disease incidence with advancing age as well as for projecting future Medicare costs.