Parents and Teens Together (PATT) is a planned digital indicated prevention program for young teens experimenting with substance use (SU) and their families that provides accessible and individualized teaching and support for implementing evidence-based family practices for SUD prevention. PATT combines a blended, virtual and health coach-led, single session intervention for personalized parent and teen instruction on evidence-based family practices with an mHealth app delivering a JITAI to support the use of those practices in daily life.