The study evaluated the impact of differentiated services (DSD) on retention in care and HIV suppression among patients on antiretroviral therapy (ART) in South Africa using target study emulation on data from 24 public health facilities. Enrolled in DSD, patients older than 18 years, on ART for at least 12 months with two suppressed viral loads were eligible. Of the 49,595 eligible subjects, 17% (25,775) were enrolled in DSD during eight 6-month periods from July 2017 to July 2021. The adjusted hazard difference for retention in care was 3.2% (95% CI [1.6%; 4.7%]) at 12 months, 4.2% (95% CI [2.4%; 4.7%]) at 12 months. 6.0%]) at 24 months and 2.4% (95% CI [0.6%; 4.2%]) at 36 months in favor of DSD. For viral suppression (<400 copies/mL), the risk difference was 1.4% to 1.7% without statistical significance. Results were consistent across time periods, with younger patients, from urban areas, or with shorter ART duration having lower retention. DSDs yielded slightly better retention and similar suppression to standard care.