Baseline CD4 testing rates declined from 73% to 21% between 2013 and 2018 with adoption of "Treat All" in Uganda. Advanced human immunodeficiency virus (HIV) disease (CD4 count < 200 cells/µL) remained common (24% of those tested in 2018, 83% of whom had World Health Organization stage I/II disease). Despite frequent presentation with advanced HIV disease, CD4 testing has declined dramatically.