ABSTRACT: BACKGROUND:HIV epidemic among young men who have sex with men (YMSM) is characterized by strong racial disparities and concerns about the availability and access to culturally appropriate HIV prevention and care service delivery. Get Connected, a Web-based intervention that employs individual- and system-level tailoring technology to reduce barriers to HIV prevention care (eg, HIV or sexually transmitted infection [STI] testing, pre-exposure prophylaxis [PrEP]), was developed for YMSM (age 15-24 years). This protocol details the design and procedures of a 2-phase project that includes mystery shopping and a randomized controlled trial (RCT) to test the efficacy of Get Connected among YMSM in Philadelphia, Atlanta, and Houston. OBJECTIVE:The objective of mystery shopping is to examine the quality of HIV test counseling and PrEP-related referrals for YMSM within local HIV or STI testing sites. The objective of the RCT is to test the efficacy of Get Connected for increasing HIV-negative or HIV-unknown YMSM's successful uptake of HIV prevention services (eg, routine HIV or STI testing), PrEP awareness, and likelihood to start PrEP (PrEP willingness), compared with those in the control condition, over a 12-month period. METHODS:For Phase 1, we will create a master list of HIV and STI testing sites in each city. We will enroll and train 10-15 mystery shoppers per city; each testing site will be separately visited and assessed by 2 mystery shoppers. After each site visit, the mystery shoppers will complete a site evaluation to record their perceptions of various measures including lesbian, gay, bisexual, transgender, queer visibility and inclusivity, privacy and confidentiality, provider-patient interactions, and clinic environment. For Phase 2, we will enroll 480 YMSM for 12 months across the 3 iTech cities into a 2-arm prospective RCT. Participants randomized to the control condition are directed to the AIDSVu.org testing site locator. Participants randomized to the intervention condition will be granted access to a Web app with content tailored to their specific demographic characteristics (eg, age, race or ethnicity, location, and relationship status), HIV and STI risk behaviors (eg, HIV and STI testing history, substance use, communication with partners regarding status) and sociocultural context (eg, homelessness, incarceration). Study assessments will occur at enrollment and at 1, 3, 6, 9, and 12 months postenrollment. RESULTS:Get Connected research activities began in September 2016 and are ongoing. To date, institutional review board (IRB) submission is complete and IRB authorization agreements are pending at several other universities. CONCLUSIONS:The deployment of Get Connected through a mobile-optimized Web app seeks to optimize the intervention's acceptability, accessibility, availability, and long-term affordability among YMSM. TRIAL REGISTRATION:ClinicalTrials.gov (NCT03132415); https://clinicaltrials.gov/ct2/show/NCT03132415 (Archived by WebCite at http://www.webcitation.org/70j4gSFbZ). REGISTERED REPORT IDENTIFIER:RR1-10.2196/10444.