Long-acting injectable (LAI) antiretroviral therapy (ART) is a novel HIV treatment option for people with HIV. The first LAI ART regimen for HIV treatment received regulatory approval in the United States in January 2021. In February 2020, we collected qualitative data from 18 consumers and 23 clinical and non-clinical stakeholders to catalog anticipated individual-consumer, healthcare system, and structural levels barriers and facilitators to LAI ART implementation in Los Angeles County, California. Thematic analysis was guided by the CFIR implementation science model. CFIR constructs of intervention characteristics, individual characteristics, outer and inner setting, intervention characteristics, and implementation process emerged in analysis. Under intervention characteristics, anticipated facilitators included the relative advantage of LAI ART over pills for adherence and reduced treatment management burden and related anxiety; anticipated barriers included non-adherence to injection appointments, concerns of developing HIV resistance, discomfort with injection and cost. Anticipated facilitators based on individual characteristics included overall acceptability based on knowledge and positive beliefs about LAI ART. Participant noted several characteristics of the outer setting that could negatively impact implementation, such as medical mistrust, external policies, and LAI ART eligibility (i.e., to be virally suppressed prior to initiation). Participants were optimistic about the potential to decrease stigma but expressed that provider willingness for adoption could be hindered by challenges in organizational inner setting related to payment authorizations, increased staffing needs, medication procurement and storage, and provider and healthcare system readiness. Results from this pre-implementation study may inform rollout and scale-up of LAI ART in Los Angeles County.