This randomized controlled trial will test the efficacy of "PrEP for Health," a behavioral intervention to improve the use of antiretroviral pre-exposure prophylaxis (PrEP) among at-risk people who inject drugs (PWID) in two syringe service program (SSP) settings in Lawrence and Boston/Cambridge, Massachusetts. The investigators will equally randomize 200 PWID to receive either (a) the "PrEP for Health" intervention condition involving theory-informed HIV and PrEP education, motivational interviewing, problem-solving and planning, and ongoing patient navigation (n=100), or (b) the standard of care condition involving PrEP information and referrals (n=100). Successful PrEP uptake (via medical/pharmacy records), post-treatment PrEP adherence (assessed at 3 months via drug levels in hair), and longer-term PrEP adherence (assessed at 6 and 12 months via drug levels in hair) will be evaluated. The degree to which intervention efficacy occurs through specific conceptual mediators and differs according to hypothesized moderators will also be evaluated.