Utilizing a mixed-methods approach that combines qualitative analyses and survey techniques, in-depth interviews were conducted with 26 patients at M. Djamil Hospital, serving a diverse patient population across Western Sumatra, Indonesia. Non-adherence was frequently attributed to factors such as medication-related boredom, forgetfulness, busyness, geographic inaccessibility to healthcare facilities, stigma, economic constraints, insurance challenges, and concerns related to COVID-19. Additionally, adverse effects of the medication, including dizziness, nausea, vomiting, sleepiness, irregular heartbeat, rash, and diarrhea were reported. Furthermore, the critical role of non-governmental organizations (NGOs) in patient support through education, medication delivery, and home visits was identified. The findings underscore a complex interplay of behavioral, socio-economic, and systemic factors underpinning non-adherence. It is posited that healthcare providers, by recognizing these determinants, can develop targeted interventions to enhance adherence, such as personalized communication strategies, including phone calls and home visits, in alignment with the UNAIDS program's long-term objectives. This study contributes to the existing literature by highlighting the multifaceted reasons behind ART nonadherence in a post-pandemic context, suggesting a need for comprehensive strategies that address both individual and structural barriers to optimize treatment outcomes for HIV/AIDS patients.