Men who have sex with men (MSM) are disproportionally affected by HIV and substance abuse in the U.S., Europe, and Latin America. However, as in the general population, identifying and engaging MSM with problematic substance use (PSU) into treatment is a significant challenge, which results in the great majority of MSM with PSU never receiving treatment. The Substance Abuse and Mental Health Services Administration (SAMHSA) recommends Screening (S), Brief Intervention (BI), and Referral to Treatment (RT; SBIRT) as an early intervention for non-treatment-seeking individuals with risky alcohol and drug use, as well as the timely referral to more intensive substance abuse treatment for those with substance use disorders. The need for such an intervention is particularly acute in Argentina and Latin America, where there is little implementation of evidence-based interventions for MSM with PSU. The proposed study seeks to address this glaring gap by developing and piloting an electronic-SBI program tailored for MSM awaiting their HIV test at Nexo Asociacion Civil, our community partners in Buenos Aires. The tablet-based e-SBI will integrate substance use and sexual risk behavior screeners and individually tailored Motivational Interviewing (MI) as the BI. We will also adapt and pilot the implementation of the Young Men’s Health Project (YMHP, now MHP since it will not be limited to young MSM), a four-session MI-based intervention that effectively reduced substance use and condomless anal intercourse among substance using MSM, as a brief treatment provided at Nexo for participants with moderate or high-risk substance use. The Specific Aims of this R34 study are to: 1) develop a tailored e-SBI intervention for MSM in an HIV testing context aimed at reducing substance use and HIV risk behavior (Primary); 2) assess the feasibility and acceptability of integrating e-SBI into the HIV testing process at Nexo as measured by a) percent of MSM testing clients at Nexo who accept entry into the study; b) percent of participants who complete e-SBI; c) e-SBI acceptability ratings (Primary); 3) assess the feasibility and acceptability of implementing adapted YMHP at Nexo, as measured by a) the percent of MSM with moderate or high-risk substance use who enter and/or complete MHP; b) acceptability of MHP among those who received it; and c) percentage of sessions conducted by each MHP counselor that meets criteria for MI fidelity (Secondary). In Stage 1 (Development) we will develop e-SBI, adapt YMHP into MHP, train MHP counselors, and pilot e-SBI with 50 MSM coming to Nexo for HIV testing. In Stage 2 (RCT Pilot), we will randomize 200 MSM coming to Nexo for HIV testing at a 3:1 ratio (eSBI: Screening Assessments Only-SA) to assess the feasibility and acceptability of e-SBI among MSM coming to Nexo for HIV testing and establish and pilot the RCT process for a future trial. As a secondary aim, we will assess uptake, acceptability, and feasibility of delivering MHP to pa...