Background Infertility affects up to 32.0% of couples in sub-Saharan Africa, while access to assisted reproductive technologies (ART), including In Vitro Fertilization (IVF), remains limited by high treatment costs. As Tanzania advances Universal Health Coverage (UHC) through the National Health Insurance Act of 2023, empirical provider cost estimates are needed to inform reimbursement and strategic purchasing. This study estimated the provider unit cost, cost structure, and cost drivers of IVF services at Muhimbili National Hospital (MNH), Tanzania. Methods A provider-perspective cross-sectional micro-costing study was conducted at MNH between January and December 2025. Bottom-up micro-costing was applied to direct costs, while top-down allocation was used for capital and indirect costs. All 10 IVF cycles initiated during the study period were included, comprising five completed and five incomplete cycles. Deterministic one-way sensitivity analysis assessed the robustness of cost estimates. Results The total provider cost for five completed IVF cycles was TZS 55,410,375.00 (USD 22,164.15), corresponding to a mean unit cost of TZS 11,082,075.00 (USD 4,432.83) per cycle. Direct costs accounted for 99.92% of the total cost, while indirect costs contributed 0.08%. Monitoring, investigation and ovarian stimulation was the largest treatment-stage cost component (55.13%). Among direct variable costs, drugs and hormones accounted for 52.67%, followed by reagents and media at 33.05%; together, these accounted for 85.72% of direct variable costs and represented the principal recurrent cost drivers. Sensitivity analysis showed that varying drugs and hormones by {+/-}15% changed the estimated provider unit cost from TZS 10,474,000 (USD 4,189.60) to TZS 11,690,125 (USD 4,676.05), while variation in reagents and media changed it from TZS 10,700,550 (USD 4,280.22) to TZS 11,463,600 (USD 4,585.44). Conclusion IVF service delivery at MNH was predominantly driven by direct clinical resource inputs. Drugs, hormones, reagents and media were the principal recurrent cost drivers. These findings provide empirical evidence to support NHIF reimbursement, strategic purchasing, and resource allocation for publicly financed IVF services in Tanzania.