Background. P3 (Prepared, Protected, emPowered) is an app that utilizes social networking and gaming to improve PrEP adherence among young men who have sex with men and transgender women (YMSM/YTW). Technology-based tools may improve patient adherence when integrated with education or counseling. We developed P3+, an extension of P3, to include adherence coaching; engaging participants in client-centered strengths-based discussions about sexual health and PrEP and assisting individuals in identifying barriers and developing tailored strategies to support PrEP adherence. Purpose. We describe the adaptation and implementation of adherence coaching and explore perceptions of the intervention. Methods. We first conducted a 30-day field test to adapt Integrated Next Step Counseling (iNSC) for delivery via text format. Next, we recruited YMSM/YTW from Houston, Tampa, Philadelphia, Chicago, Boston, and New York City (Bronx) to participate in a three-arm randomized controlled trial (SOC, P3, P3+). Eighty-one participants received the P3+ intervention for 3 months. Participants were offered up to 8 adherence coaching sessions during the intervention. We then conducted a survey and qualitative interviews (n=14) at 3-months. Results. We found that the iNSC techniques based on verbal communication (e.g., providing affirmations) were easily translated to text format and accepted by participants, whereas reflective listening statements (e.g., paraphrasing) were not well received by participants as they caused delays in the responses from coaches. Also, we found that quick responses from coaches were essential for active engagement. In the RCT, participants attended on average, 3 coaching sessions. Approximately 91% of participants (n=61/67) trusted the information they received from their coach, and ~71.6% believed their coach helped them solve any PrEP-related problems. A thematic analysis found adherence coaching was generally acceptable and engaging. Themes across interviews related to the benefits of coaches (e.g., resourceful), preferences for engagement (e.g., call vs. text), coach rapport (e.g., personable), and coaching topics (e.g., PrEP experiences, sexual health). A few participants reported not needing adherence coaching due to having access to similar resources. Conclusions. Adherence coaching delivered via in-app texting based on iNSC was feasible and acceptable and should be explored further as a companion to digital health interventions.