Aim: To estimate the cost-effectiveness of the EmERGE Pathway of Care for medically stable people living with HIV (PLHIV) at the University Hospital for Infectious Diseases (UHID), Zagreb. The Pathway includes a mobile application enabling individuals to communicate with their caregivers. ----- Methods: This study involving 293 participants collected data on the use of HIV outpatient services one year before and after EmERGE implementation. In departments supporting HIV outpatients, a micro-costing exercise was performed to calculate unit costs. These were combined with mean use of HIV services per patient year (MPPY) to estimate average annual costs. Primary outcomes were CD4 count, viral load, and secondary outcomes were patient activation, PAM13; and quality of life, PROQOL-HIV. Information on out-of-pocket expenditures was also collected. ----- Results: Outpatient visits decreased by 17%, from 4.0 (95% CI 3.8-4.3) to 3.3 MPPY (95% CI 3.1-3.5). Tests, including CD4 count, decreased, all contributing to a 33% reduction of annual costs: 7139 HRK (95% CI 6766-7528) to 4781 HRK (95% CI 4504-5072). Annual costs including anti-retroviral drugs (ARVs) decreased by 5%: 43101 HRK (95% CI 42728-43,490) to 40 743 HRK (95% CI 40466-41,034). ARVs remain the main cost driver in stable PLHIV. Primary and secondary outcomes did not change substantially between periods. ----- Conclusion: EmERGE Pathway was a cost-saving intervention associated with changes in management, and a reduction in outpatient visits, tests, and costs. ARV costs dominated costs. Future efficiencies are possible if EmERGE is introduced to other PLHIV across the UHID and if ARV prices are reduced.