Inclusion Criteria:  Age 18-89 years Receiving TFV (as TAF or TDF) and FTC based antiretroviral therapy for the treatment of HIV Current patient at the UCH IDGP clinic Able to comply with study procedures, including directly observed self-collection of DBS via fingerstick and completion of survey  Exclusion Criteria:  Active hemolysis or symptomatic hemoglobinopathies Inability to provide informed consent Unable to comply with directly observed self-collection of DBS (e.g., unavailable or unable to use video streaming or recording technology)