A critical issue in cross-sectional aging studies is the comparability of subjects of different ages, particularly regarding health status. For example, it is typically assumed that healthy 60-year-old men are equivalent to healthy 80-year-old men when both age groups are selected using the same criteria. The 60-year-old, however, may not survive or be healthy at age 80. To examine this issue, 212 healthy 60-year-old men in the Baltimore Longitudinal Study of Aging were identified. By life table analysis, 30% were expected to survive and remain healthy to age 80. In this study, 61 healthy 60-year-old men were followed to age 80. When compared with 125 healthy 80-year-old men, they had more heart disease, cancer, stroke, arterial, digestive, and peripheral nervous system diseases. Twenty-seven of the 61 men (44%) actually continued to be healthy at age 80. At age 60, systolic pressure and total serum cholesterol were predictive of who would be healthy at age 80.