(1) Background: Adolescents and young adults face challenges when transitioning to adult care due to emerging adulthood and changing providers and insurance. Young people living with HIV (YPLHIV) have additional obstacles with mental health and stigma. During transition, only 55% of YPLHIV are retained in care, and 65% are virally suppressed. To address these challenges, the Adolescent and Young Adult Health Care Transition Clinic (AYAHCTC) was created at Vanderbilt University Medical Center in 2017. This mixed methods study evaluates the initial cohort and solicits YPLHIVs' perspectives on transition barriers and facilitators. (2) Methods: Quantitative analyses (n = 21) characterized patients' demographics, clinical engagement, and retention. Qualitative interviews (n = 5) captured patients' transition experiences. (3) Results: This study, conducted in the Southeastern USA, included a cohort where 47.6% were born abroad, with all participants being US citizens by birth or naturalization. Patients' mean age at first visit was 19.6 years. The average AYAHCTC duration was 2.21 years. First-year engagement and retention were 100% and 95.5%, respectively. Viral suppression rates improved from 66.7% at the first visit to 81.0% at the last visit. Eleven patients transitioned out of AYAHCTC. Qualitative analyses indicate that barriers to transition include leaving trusted providers, reduced parental guidance, developing autonomy, and perceived loss of confidentiality in adult clinic environment. Transition was facilitated by youth-friendly services, clear communication, and strong relationships with AYAHCTC providers. (4) Conclusions: YPLHIV positively viewed AYAHCTC experiences. Future directions include optimizing services to build YPLHIVs' independence, supporting YPLHIV experiencing stigma, assuaging concerns about switching providers, collaborating with adult clinics to maintain confidentiality, and designing interventions focused on adherence during transition.