['Therapies to achieve sustained antiretroviral therapy-free HIV remission will require validation in analytic treatment interruption (ATI) trials. Identifying biomarkers that predict time to viral rebound could accelerate the development of such therapeutics.', 'A pooled analysis of participants from six AIDS Clinical Trials Group ATI studies to identify predictors of viral rebound.', 'Cell-associated DNA (CA-DNA) and CA-RNA were quantified in pre-ATI peripheral blood mononuclear cell samples, and residual plasma viremia was measured using the single-copy assay.', 'Participants who initiated antiretroviral therapy (ART) during acute/early HIV infection and those on a non-nucleoside reverse transcriptase inhibitor-containing regimen had significantly delayed viral rebound. Participants who initiated ART during acute/early infection had lower levels of pre-ATI CA-RNA (acute/early vs. chronic-treated: median <92 vs. 156 HIV-1 RNA copies/10 CD4 cells, P\u200a<\u200a0.01). Higher pre-ATI CA-RNA levels were significantly associated with shorter time to viral rebound (≤4 vs. 5-8 vs. >8 weeks: median 182 vs. 107 vs. <92 HIV-1 RNA copies/10 CD4 cells, Kruskal-Wallis P\u200a<\u200a0.01). The proportion of participants with detectable plasma residual viremia prior to ATI was significantly higher among those with shorter time to viral rebound.'] Does the size of the expressed HIV reservoir predict timing of viral rebound after treatment interruption?