Disparities in HIV treatment outcomes among youth living with HIV (YLWH) present a challenge for ending the HIV epidemic. Antiretroviral therapy (ART) adherence can be impacted by comorbidities such as mental health and substance use. Technology use has shown promise in increasing access to mental health and substance use services. Using a mixed-methods approach, we conducted formative research to describe the relationship between mental health, substance use, and medication adherence in 18-29 year-old YLWH, and explored technology use as an approach to supporting these services. Among 101 YLWH, ART adherence was significantly negatively associated with mental health measures such as depression, trauma, and adverse childhood experiences and marijuana and stimulants use. Depression had the highest level of relative importance in its association with ART adherence. During in-depth interviews with 29 participants, barriers to and facilitators of accessing and maintaining mental health services were identified. Most participants favored technology use for mental health and substance use service delivery, including videoconferencing with a counselor. Provision of ongoing mental health and substance use treatment is an important mechanism to achieving HIV treatment engagement. Technology, particularly videoconferencing, may have the capacity to overcome many barriers to care by increasing accessibility of these services.