Abstract This project will launch a Florida wide effort to promote the delivery of developmentally sensitive, culturally appropriate and evidence-based DIAGNOSE and PREVENT counseling testing and referral services (CTR) for young men who have sex with men (YMSM). The goal is to leverage implementation science strategies to improve the capacity of the HIV HealthForce to deliver evidence-based practices (risk reduction counseling, PrEP referral and Tailored Motivational Interviewing) within CTR services. Our recent YMSM Mystery Shoppers studies conducted at CTR sites in three cities indicated that providers are woefully unprepared or do not know how to deliver developmentally appropriate, culturally competent CTR services to YMSM and miss opportunities to deliver these evidence-based practices. Mystery Shopper is a quality management strategy to monitor implementation fidelity to culturally and developmentally responsive EBPs in CTR settings. However, assessment and feedback alone are insufficient to improve fidelity; the HealthForce must be properly trained and given technical assistance. We propose integrating two implementation strategies: quality management Mystery Shoppers and HealthForce training in Tailored Motivational Interviewing with centralized technical assistance. We will test Young Adult Centered HealthForce Training (YACHT) package in Florida’s seven EHE counties among the Department of Health’s 42 contracted sites who delivered CTR to at least 24 young MSM in the previous 12 months using a Stepped Wedge design. We power on both effectiveness outcomes (# of tests of YMSM) and implementation outcomes (EBP fidelity based on Mystery Shopper Assessments) consistent with a Type 2 Hybrid trial.