Importance:Evidence suggests that the quality of some aspects of care provided by physicians may decrease during their late career stage. However, to our knowledge, data regarding the association of advancing surgeon career phase with cataract surgical outcomes have been lacking. Objective:To investigate whether an increase in cataract surgical adverse events occurs during later surgeon career stages. Design, Setting, and Participants:This population-based study of 499 650 cataract operations performed in Ontario, Canada, between January 1, 2009, and December 31, 2013, investigated the association between late surgeon career stage and the risk of surgical adverse events. Linked health care databases were used to study cataract surgical complications while controlling for patient-, surgeon-, and institution-level covariates. All ophthalmologists who performed cataract surgery in Ontario within the study period were included in the analysis. Exposures:Isolated cataract surgery performed by surgeons at early, mid, and late career stages. Main Outcomes and Measures:Four serious adverse events were evaluated: dropped lens fragments, posterior capsule rupture, suspected endophthalmitis, and retinal detachment. Results:Of 416 502 participants, 244 670 (58.7%) were women, 90 429 (21.7%) were age 66 to 70 years, 111 530 (26.8%) were age 71 to 75 years, 90 809 (21.8%) were age 76 to 80 years, and 123 734 (29.7%) were 81 years or older. Late-career surgeons performed 143 108 of 499 650 cataract operations (28.6%) during the study period. Late surgeon career stage was not associated with an increased overall risk of surgical adverse events (odds ratio [OR] vs midcareer, 1.06; 95% CI, 0.85-1.32). In a sensitivity analysis with surgeon volume removed from the model, late career stage was still not associated with overall adverse surgical events (OR, 1.10; 95% CI, 0.88-1.38). Among individual complications, late surgeon career stage was associated with an increased risk of dropped lens fragment (OR, 2.30; 95% CI, 1.50-3.54) and suspected endophthalmitis (OR, 1.41; 95% CI, 1.01-1.98). These corresponded with small absolute risk differences of 0.11% (95% CI, 0.085%-0.130%) and 0.045% (95% CI, 0.028%-0.063%) for dropped lens fragment and suspected endophthalmitis, respectively. Conclusions and Relevance:These findings suggest that later-career surgeons are performing a substantial proportion of cataract operations with overall low surgical adverse event rates. Future studies might extend evaluations to the frequency of secondary surgical interventions as additional measures of surgical care quality.