INTRODUCTION: The Temprano and START trials provided evidence to support early ART initiation recommendations. We projected long-term clinical and economic outcomes of immediate ART initiation in Cote d'Ivoire. METHODS: We used a mathematical model to compare three potential ART initiation criteria: 1) CD4 <350/muL (ART<350/muL); 2) CD4 <500/muL (ART<500/muL); and 3) ART at presentation (Immediate ART). Outcomes from the model included life expectancy, 10-year medical resource use, incremental cost-effectiveness ratios (ICERs) in $/year of life saved (YLS), and 5-year budget impact. We simulated people with HIV (PWH) in care (mean CD4: 259/muL, SD 198/muL) and transmitted cases. Key input parameters to the analysis included first-line ART efficacy (80% suppression at 6 months) and ART cost ($90/person-year). We assessed cost-effectiveness relative to Cote d'Ivoire's 2017 per capita annual gross domestic product ($1,600). RESULTS: Immediate ART increased life expectancy by 0.34 years compared to ART<350/muL and 0.17 years compared to ART<500/muL. Immediate ART resulted in 4,500 fewer 10-year transmissions per 170,000 PWH compared to ART<350/muL. In cost-effectiveness analysis, Immediate ART had a 10-year ICER of $680/YLS compared to ART<350/muL, ranging from cost-saving to an ICER of $1,440/YLS as transmission rates varied. ART<500/muL was "dominated" (an inefficient use of resources), compared with Immediate ART. Immediate ART increased the 5-year HIV care budget from $801.9M to $812.6M compared to ART<350/muL. CONCLUSIONS: In Cote d'Ivoire, immediate compared to later ART initiation will increase life expectancy, decrease HIV transmission, and be cost-effective over the long-term, with modest budget impact. Immediate ART initiation is an appropriate, high-value standard of care in Cote d'Ivoire and similar settings.Read less <