Opt4TPT is an observational study of TB preventive therapy provision among people living with HIV in South Africa, Zimbabwe, and Ethiopia. The goal is to describe TB preventive therapy delivery, uptake, and adherence as well as side effects and incident TB among those started or not started on TB preventive therapy. In addition, TB preventive therapy clinic workflows are being characterized through value stream mapping, in-depth interviews, and audio-recording of patient-provider interactions.