Scale-up of Option B+ in Zimbabwe has increased antiretroviral therapy (ART) coverage but patient loss-to-follow-up remains high; thus, effective strategies to improve retention in care are needed. Evidence for Elimination, a cluster randomized controlled trial, evaluated the impact of point-of-care (POC) CD4 testing with CD4 count-specific adherence counseling on rates of retention among 1150 HIV-positive pregnant women initiating ART in Zimbabwe.