Total disc replacement (TDR) has become a viable alternative to anterior cervical discectomy and fusion (ACDF) for select patients. Although most comparative studies have assessed outcomes, cost differences remain largely uninvestigated. This information is critical as we move towards value-based reimbursement. To address this knowledge gap, we used time-driven activity-based costing (TDABC) to compare total intraoperative costs between the two procedures. Total cost was divided into direct (personnel and supply cost) and indirect costs (administrative and overhead costs). Individual costs were determined through direct observation, electronic medical records, and through querying multiple departments (including business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented, in conjunction with process mapping of the intraoperative period. Total intraoperative costs were estimated for all ACDFs (n=810) and TDRs (n=54) from 2017 to 2022. Regression analyses were performed to identify factors associated with total cost. A total of 810 and 54 patients underwent one- and two-level ACDFs and TDRs, respectively. The average total intraoperative cost for an ACDF was $6,776 +/- $2,808, compared to $12,026 +/- $4,235 for TDR. Supply cost accounted for the majority of total cost for both procedures ($4,173 +/- $2,225 for ACDF and $9,532 +/- $4,010 for TDR). On multivariable linear regression analysis, TDR was associated with roughly $3,885 of additional cost compared to ACDF (p<0.001), as well as $4,072 in additional supply cost (p<0.001), most of which was driven by the higher cost of implants (p<0.001). TDABC is a highly useful methodology for estimating differences in true costs between procedures and determining cost drivers. TDRs were associated with an additional $3,885 of total intraoperative cost as compared to ACDFs, the majority of which was driven by the cost of implants.