OBJECTIVE: To assess the economics of secondary IOL surgeries, with a focus on variations in day-of-surgery costs based on surgical approach and number of surgeons involved. DESIGN: Retrospective, time-driven, activity-based costing study analyzing costs and reimbursement rates. SETTING: University of Michigan Kellogg Eye Center, analyzing procedures performed between January 1, 2014 and December 31, 2023. PARTICIPANTS: Patients undergoing secondary IOL surgeries, including both single- and multi-surgeon cases and procedures without vitrectomy, with anterior vitrectomy, and with pars plana vitrectomy (PPV). METHODS: Data were obtained from the institution's Electronic Health Record and Revenue Department secondary IOL surgeries (CPT codes 66985 and 66986) performed over ten years at a single academic institution. Time-driven activity-based costing was applied to calculate the costs associated with each procedure. Primary outcomes were the total cost, reimbursement, and net margins for secondary IOL surgeries. Secondary outcomes were surgical times, time-related costs, and materials costs. RESULTS: 391 cases were included in this analysis over a ten-year period, including 145 without vitrectomy, 56 with anterior vitrectomy, and 190 with PPV. There was no difference in primary or secondary outcome measures between IOL insertion (CPT 66985) and IOL exchange (CPT 66986). The total day-of-surgery costs were 248.40-447.15 for secondary IOL without vitrectomy, 245.05-600.36 for secondary IOL with anterior vitrectomy, 518.52-272.21 for single-surgeon secondary IOL with PPV, and 769.22-609.39 for multiple-surgeon secondary IOL with PPV. The calculated Medicare reimbursements were 771.67-901.81 for secondary IOL without vitrectomy, 005.66-155.75 for secondary IOL with anterior vitrectomy, and 813.26-861.62 for secondary IOL with PPV. Therefore, the net margins were -(675.48-347.59) for secondary IOL without vitrectomy, -(444.60-239.39) for secondary IOL with anterior vitrectomy, -(04.26-10.59) for single-surgeon secondary IOL with PPV, and -(796.13-907.60) and for multiple-surgeon secondary IOL with PPV. CONCLUSIONS: All secondary IOL surgeries result in net negative margins with single-surgeon PPV cases having the most favorable reimbursement that covers 87-92% of day-of-surgery costs and multiple-surgeon PPV surgeries having the least favorable with only 56-63% of costs reimbursed. Identifying these cost-intensive procedures offers insights for potential cost-reduction strategies, supporting both economic viability and patient access to necessary eye care.