ImportanceMany veterans enrolled in the Veterans Affairs (VA) health care system have access to non-VA care through insurance and VA-purchased community care. Prior comparisons of VA and non-VA hospital outcomes have been limited to subpopulations.ObjectiveTo compare outcomes for 6 acute conditions in VA and non-VA hospitals for younger and older veterans using VA and all-payer discharge data.Design, Setting, and ParticipantsThis cohort study used a repeated cross-sectional analysis of hospitalization records for acute myocardial infarction (AMI), coronary artery bypass graft (CABG), gastrointestinal (GI) hemorrhage, heart failure (HF), pneumonia, and stroke. Participants included VA enrollees from 11 states at VA and non-VA hospitals from 2012 to 2017. Analysis was conducted from July 1, 2022, to October 18, 2023.ExposuresTreatment in VA or non-VA hospital.Main Outcome and MeasuresThirty-day mortality, 30-day readmission, length of stay (LOS), and costs. Average treatment outcomes of VA hospitals were estimated using inverse probability weighted regression adjustment to account for selection into hospitals. Models were stratified by veterans’ age (aged less than 65 years and aged 65 years and older).ResultsThere was a total of 593 578 hospitalizations and 414 861 patients with mean (SD) age 75 (12) years, 405 602 males (98%), 442 297 hospitalizations of non-Hispanic White individuals (75%) and 73 155 hospitalizations of non-Hispanic Black individuals (12%) overall. VA hospitalizations had a lower probability of 30-day mortality for HF (age ≥65 years, −0.02 [95% CI, −0.03 to −0.01]) and stroke (age <65 years, −0.03 [95% CI, −0.05 to −0.02]; age ≥65 years, −0.05 [95% CI, −0.07 to −0.03]). VA hospitalizations had a lower probability of 30-day readmission for CABG (age <65 years, −0.04 [95% CI, −0.06 to −0.01]; age ≥65 years, −0.05 [95% CI, −0.07 to −0.02]), GI hemorrhage (age <65 years, −0.04 [95% CI, −0.06 to −0.03]), HF (age <65 years, −0.05 [95% CI, −0.07 to −0.03]), pneumonia (age <65 years, −0.04 [95% CI, −0.06 to −0.03]; age ≥65 years, −0.03 [95% CI, −0.04 to −0.02]), and stroke (age <65 years, −0.11 [95% CI, −0.13 to −0.09]; age ≥65 years, −0.13 [95% CI, −0.16 to −0.10]) but higher probability of readmission for AMI (age <65 years, 0.04 [95% CI, 0.01 to 0.06]). VA hospitalizations had a longer mean LOS and higher costs for all conditions, except AMI and stroke in younger patients.Conclusions and RelevanceIn this cohort study of veterans, VA hospitalizations had lower mortality for HF and stroke and lower readmissions, longer LOS, and higher costs for most conditions compared with non-VA hospitalizations with differences by condition and age group. There were tradeoffs between better outcomes and higher resource use in VA hospitals for some conditions.