Adherence to care and antiretroviral therapy is challenging, especially for people living with HIV (PLWH) with additional co-occurring risk factors. Case management interventions, including motivational interviewing (MI), show promise to improve HIV treatment adherence, but few studies have examined how such interventions are delivered to or experienced by PLWH who have been reengaged in care. We conducted qualitative interviews with six case managers and 110 PLWH exiting from a randomized study (HPTN 078) who received a MI-based case management intervention in addition to standard patient-navigation services, or standard services only. Our study provided greater insight into the main findings from HPTN 078, including an in-depth description of the multiple barriers to adherence faced by this largely "out-of-care" population, as well as a more nuanced understanding of the benefits and challenges of implementing MI. A blend of MI plus more intensive interventions may be needed for PLWH facing multiple structural barriers.