center dot OBJECTIVE: To assess the economics of secondary intraocular lens (IOL) surgeries, with a focus on variations in day-of-surgery costs based on surgical approach and number of surgeons involved. center dot DESIGN: Retrospective, time-driven, activity-based costing study analyzing costs and reimbursement rates. center dot SETTING: University of Michigan Kellogg Eye Center, analyzing procedures performed between January 1, 2014, and December 31, 2023. center dot 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). center dot METHODS: Data were obtained from the institution's Electronic Health Record and Revenue Department secondary IOL surgeries (Current Procedural Terminology [CPT] codes 66985 and 66986) performed over 10 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 material costs. center dot RESULTS: A total of 391 cases were included in this analysis over a 10-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 $4248.40 to $4447.15 for secondary IOL without vitrectomy, $4245.05 to $4600.36 for secondary IOL with anterior vitrectomy, $5518.52 to $5272.21 for single-surgeon secondary IOL with PPV, and $7769.22 to $8609.39 for multiple-surgeon secondary IOL with PPV. The calculated Medicare reim bursements were $2771.67 to $2901.81 for secondary IOL without vitrectomy, $3005.66 to $3155.75 for secondary IOL with anterior vitrectomy, and $4813.26 to $4861.62 for secondary IOL with PPV. Therefore, the net margins were-($1675.48-$1347.59) for secondary IOL without vitrectomy,-($1444.60-$1239.39) for secondary IOL with anterior vitrectomy,-($704.26$410.59) for single-surgeon secondary IOL with PPV, and-($3796.13-$2907.60) for multiple-surgeon secondary IOL with PPV. center dot CONCLUSIONS: All secondary IOL surgeries result in net negative margins with single-surgeon PPV cases having the most favorable reimbursement that covers 87% to 92% of day-of-surgery costs and multiple-surgeon PPV surgeries having the least favorable with only 56% to 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. (Am J Ophthalmol 2025;273: 159-166. (c) 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)