OBJECTIVE: To determine (1) the rate at which rescreening former Department of Energy site workers identifies non-communicable chronic diseases and (2) the development of comorbid conditions. METHODS: Incidence and prevalence of hypertension, diabetes, reduced kidney function, and peripheral neuropathy at both initial and return screenings were calculated. Risk ratio of chronic disease development at return screening based on the presence of other conditions at initial screening were estimated with generalized linear regression. RESULTS: Prevalence of reduced kidney function was 19% at initial exam and 30% at return examination. The screening program was responsible for identifying 81% of reduced kidney function cases. Similar findings were present for the other chronic conditions examined. CONCLUSIONS: Former worker health surveillance programs help identify significant health conditions among DOE workers, subcontractors, and visitors. Longitudinal screening of participants detects additional chronic conditions.