Purpose: To perform a time-driven, activity-based cost analysis of retinal detachment (RD) surgery and compare it with reimbursement rates. Methods: This economic analysis at a single academic institution used time-driven, activity-based costing methodology to determine the cost of rhegmatogenous RD repair with primary pars plana vitrectomy. A process flow map was created to highlight each surgical case’s operative episodes, including clinical follow-ups. Time logs were obtained from the electronic health record for each operative phase and clinical follow-up. The overhead and anesthesia costs were collected from the institution’s cost accounting system. The direct material and personnel costs were obtained from internal financial data. Results: Seventy-six cases that met the inclusion criteria were included in the cost analysis study. The time-driven, activity-based cost of RD was $6247.17, and the reimbursement was $5442.91. Therefore, each procedure had a net negative loss of $804.26. To break even, the average operation time would need to be reduced from the determined average of 90.49 minutes to 64.90 minutes. Conclusions: This study found that Medicare underestimates the true cost of RD surgery. Changes in referral patterns may be motivated by reimbursement rates lower than the cost of the procedure, which could ultimately affect patient access to care.