The purpose of this study is to determine the feasibility of a future trial that will assess whether an integrated intervention combining psychosocial counseling and supported referrals for antiretroviral therapy (ART) at any CD4 cell count and substance use treatment for HIV-infected people who inject drugs (PWID) will reduce HIV transmission to HIV-uninfected injection partners, as compared to routine care dictated by national guidelines for HIV-infected PWID.