Hypotheses about the extent, persistence, and constancy for different causes of the healthy worker effect are evaluated using the data of the Dorn Study of Mortality Among US Veterans. Those data were selected because persons who qualify to serve in the armed forces have health status comparable to that of persons able to seek employment. Mortality rates for 5-year age groups and standardized mortality ratios for younger, older, and all age groups were computed and compared to those of the US population for all causes, all cancers, heart disease, stroke, and selected other causes of death. A healthy worker effect of 20% to 40% reduced mortality was shown to persist over the entire age range for the various causes. The overall effect for all causes is 27%.