<h4>Introduction</h4>We investigated the impact of increasing CD4 count eligibility for antiretroviral therapy (ART) initiation on advanced HIV disease (AHD) and tuberculosis (TB) prevalence and incidence among people living with HIV (PLHIV) in South Africa.<h4>Methods</h4>We conducted an interrupted time series analysis with de-identified data of PLHIV aged ≥15 years initiating ART between April 2012 and February 2020 at 65 primary healthcare clinics in KwaZulu-Natal, South Africa. This evidence concerns the gene CD4 and tuberculosis.