Introduction Voluntary medical male circumcision (VMMC) clients are required to attend multiple post-operative follow-up visits in South Africa (SA). However, up to 98% of VMMC clients heal without adverse events (AEs). With demonstrated VMMC safety across global programs, stretched clinic staff in SA may conduct more than 400,000 unnecessary reviews for males without complications per year. As part of a randomized controlled trial (RCT) to test two-way texting (2wT) follow-up as compared to routine, in-person visits for adult VMMC clients, the objective of this study was to compare costs of 2wT-based telehealth to routine post-VMMC care in both rural and urban SA settings. Methods We used an activity-based costing (ABC) approach to estimate the costs in post-VMMC care, including counselling, follow-ups, and tracing activities. All costs were estimated in $US dollars for both 2wT and routine care to test the hypotheses that 2wT follow-up would result in per-client cost savings. Data were collected from routine National Department of Health VMMC forms, the RCT database, and time-and-motion surveys. Sensitivity analysis presents different scale-up scenarios. Results We included 1,084 clients: 537 in routine care and 547 in 2wT. Average client follow-up cost is $6.48 for routine care and $4.25 for 2wT. 2wT saved costs in both rural and urban locations. Average savings of $2.23 was greater in rural ($1.61) than urban areas ($0.62). 2wT would save $0.88, $2.23, and $4.93, respectively, if: men attended one visit; men attended visits in similar proportions to that observed in the RCT; and men attended both visits. Conclusion 2wT reduces post-VMMC care costs by supporting most men to heal at home while using telehealth to triage clients with potential AEs to timely, in-person care. 2wT savings are higher in rural areas. Scale-up of 2wT-based follow-up could significantly reduce overall VMMC costs while maintaining service quality.