Background Cardiac rehabilitation (CR) is strongly recommended after percutaneous coronary intervention (PCI), but it is underused. We sought to evaluate CR participation variation after PCI and its association with mortality among veterans. Methods and Results Patients undergoing PCI between 2007 and 2011 were identified in the Veterans Affairs Clinical Assessment, Reporting, and Tracking database and followed up until January 25, 2017. We excluded patients who died within 30 days of PCI and calculated the percentage participating in ≥1 outpatient CR visits within 12 months after PCI. We constructed multivariable hierarchical logistic regression models for CR participation, clustered by facility. We estimated propensity scores for CR participation, matched participants and nonparticipants by propensity score, calculated mortality rates, and estimated the association with mortality using Cox proportional hazards models. Participation in CR after PCI was 6.9% (2986/43 319) and varied significantly by PCI facility (range, 0%-36%). After 6.1 years median follow-up, CR participants had a 33% lower mortality rate than all nonparticipants (3.8 versus 5.7 deaths/100 person-years; hazard ratio, 0.67; 95% confidence interval, 0.61-0.75; P<0.001) and a 26% lower mortality rate than 2986 propensity-matched nonparticipants (3.8 versus 5.1 deaths/100 person-years; hazard ratio, 0.74; 95% confidence interval, 0.65-0.84; P<0.001). Participants attending ≥36 sessions had the lowest mortality rate (2.4 deaths/100 person-years; hazard ratio, 0.47; 95% confidence interval, 0.36-0.60; P<0.001). Conclusions CR participation after PCI among veterans is low overall, with significant facility-level variation. CR participation is associated with lower mortality rates in veterans. Additional efforts are needed to promote CR participation after PCI among veterans.