Mobile service delivery in response to the opioid epidemic in Philadelphia.

Background: The harms of opioid use disorder (OUD) and HIV infection disproportionately impact marginalized populations, especially people experiencing homelessness and people who inject drugs (PWID). Mobile OUD service delivery models are emerging to increase access and reduce barriers to OUD care. While there is growing interest in these models, there is limited research about the services they provide, how they operate, and what barriers they face.