We modeled the cost-effectiveness of laboratory-based “reflex” CrAg screening for ART-naïve CrAg-positive patients with CD4<100 cells/μL (those currently targeted in guidelines) and ART-experienced CrAg-positive patients with CD4<100 cells/μL (who make up an increasingly large proportion of individuals with advanced HIV/AIDS). The gene discussed is CD4; the disease is AIDS.