ABSTRACT: OBJECTIVES:To assess the incidence of chronic illness and its effect on veteran centenarians. DESIGN:Retrospective longitudinal cohort study. SETTING:United States Veterans Affairs Corporate Data Warehouse (CDW). PARTICIPANTS:Community-dwelling veterans born between 1910 and 1915 who survived to at least age 80 (N = 86,892; 31,121 octogenarians, 52,420 nonagenarians, 3,351 centenarians). MEASUREMENTS:The Kaplan-Meier method was used to estimate cumulative incidence of chronic conditions according to age group. Incidence rates were compared using the log-rank test. Cox proportional hazards models were used to estimate unadjusted hazard ratios. RESULTS:Ninety-seven percent of Centenarians were male, 88.0% were white, 31.8% were widowed, 87.5% served in World War II, and 63.9% did not have a service-related disability. The incidence rates of chronic illnesses were higher in octogenarians than centenarians (atrial fibrillation, 15.0% vs 0.6%, P < .001; heart failure, 19.3% vs 0.4%, P < .001; chronic obstructive pulmonary disease, 17.9% vs 0.6%, P < .001; hypertension, 29.6% vs 3.0%, P < .001; end-stage renal disease, 7.2% vs 0.1%, P < .001; malignancy, 14.1% vs 0.6%, P < .001; diabetes mellitus, 11.1% vs 0.4%, P < .001; stroke, 4.6% vs 0.4%, P < .001) and in nonagenarians than centenarians (atrial fibrillation, 13.2% vs 3.5%, P < .001; heart failure, 15.8% vs 3.3%, P < .001; chronic obstructive pulmonary disease, 11.8% vs 3.5%, P < .001; hypertension, 27.2% vs 12.8%, P < .001; end-stage renal disease, 11.9% vs 4.5%, P < .001; malignancy, 8.6% vs 2.3%, P < .001; diabetes mellitus, 7.5% vs 2.2%, P < .001; and stroke, 3.5% vs 1.3%, P < .001). CONCLUSION:In a large cohort of predominantly male community-dwelling elderly veterans, centenarians had a lower incidence of chronic illness than those in their 80s and 90s, demonstrating similar compression of morbidity and extension of health span observed in other studies.