This report presents mortality rates following inpatient admissions for the 20 most frequent DRG categories among Medicare inpatients aged > or = 65 years at Connecticut acute-care hospitals during the three-year period from fiscal year 1991 to fiscal year 1993. We provide frequency distributions of the 30-day and 365-day mortality rates among these 20 DRG categories. Among the 199,680 discharges of elderly Medicare beneficiaries within the 20 most frequent DRG categories in the three-year study period, the crude 30-day mortality rate was 9.51%; the crude 365-day mortality rate was 28.40%. By gender, the crude 30-day mortality rate for women was 8.78%; the corresponding rate for men was 10.48%. This gender mortality differential occurred despite a significant age differential; on average, the females were 2.5 years older than the males. By age group, the crude mortality rates were: age 65-74 years, 6.66%; age 75-84 years, 9.80%; age > or = 85 years, 15.25%. The crude mortality rates for the DRG categories were found to be stable over the three-year study period.