Abstract: OBJECTIVES: We examined long-term patterns of posttraumatic stress disorder (PTSD) and behavioral outcomes in Vietnam veterans. METHODS: A random sample of 12,400 veterans was surveyed in 1984, 1998, and a deployed subset (n = 729) in 2020. Outcomes included PTSD, psychological well-being, health functioning, and disability. RESULTS: Four PTSD patterns emerged over 35 years: current PTSD (9.1%, rising to 15.5% in heavy combat), prior PTSD (9.7%), subthreshold PTSD (25.2%), and never PTSD (56.0%). A strong combat-PTSD dose-response relationship persisted across time points. Veterans with current PTSD showed the worst outcomes; those with subthreshold or prior PTSD had intermediate outcomes, while never-PTSD veterans fared best. Community support mitigated adverse effects. CONCLUSIONS: Findings highlight the enduring impact of combat, with PTSD and related dysfunction affecting veterans even below clinical thresholds, leaving many ineligible for Department of Veterans Affairs (DVA) programs.