This qualitative study employed a phenomenological approach and aimed to understand experiences towards HIV/AIDS medical and nursing service during the COVID-19 pandemic among people living with HIV (PLHIV), and healthcare providers. This study also explored medical and nursing service model of HIV/AIDS follow-up during the COVID-19 pandemic. Narrative interview and group interviews were conducted among 34 participants (14 health providers (nurses, pharmacists, and public health workers), 14 PLHIV, and 6 physicians) from April 2021 to February 2022 in the hospitals of the 5th health service region, Thailand. Interviews were audio-recorded, transcribed verbatim, coded for themes and sub-themes, and analyzed using a phenomenological approach for thematic content analysis The finding was showed medical treatment in HIV-AIDS patients before the COVID-19 epidemic period. These are included a medical treatment plan in the hospital and an Out-of-hospital care plans. A medical treatment plan in the hospital is a primarily assessed from the patient's symptoms which are included patient who has an unstable or uncontrol symptoms and require a close supervision for further assessment. In addition, patients who need a follow-up appointments or clinical visits should be assessed for a period of time, such as physical examination, blood tests and other necessity examinations. An Out-of-hospital care plan is a treatment that joint decision between service providers and patient and focused in patient centered care. The finding was showed medical treatment in HIV-AIDS patients in the COVID-19 epidemic period. The result revealed that there were three primary themes, including: (1) new normal in HIV/AIDS medical and nursing service during the COVID-19 pandemic, (2) participative management of HIV/AIDS medical and nursing service during the COVID-19, and (3) factors contributing to succeed of HIV/AIDS medical and nursing service delivery. In theme 1, interview data revealed four subthemes pertaining to new normal of HIV/AIDS medical and nursing service during the COVID-19 pandemic: (1) reducing HIV/AIDS medical and nursing service step, (2) rotation of PLHIV group service, (3) using alternative methods to get medications during the COVID-19 pandemic, and (4) modification of HIV/AIDS medical and nursing service environment. During the COVID-19 pandemic, the participants stated that their quality of life has not changed. Additionally, the COVID-19 prevention measures (i.e., wearing face mask, hand washing, and avoiding crowded places) were extremely practiced. In theme 2, interview data demonstrated two subthemes regarding participative management of HIV/AIDS medical and nursing service during the COVID-19: (1) communication within the organization to reach mutual understanding, and (2) networking. In theme 3, interview data demonstrated three subthemes regarding factors contributing to succeed of HIV/AIDS medical and nursing service delivery: (1) effort of team members to deliver excellent service, (2) administrator’s support, and (3) awareness of self-management among clients. This study provides a backdrop for the implementation of nursing interventions that will be designed to reshape flexible medical and nursing service for Thai PLHIV during the COVID-19 pandemic.