There continues to be a gap in prevention outcomes achieved in research trials vs. “real world” practice. This article summarizes interim findings from a randomized trial testing Assets-Getting To Outcomes (AGTO), a two-year intervention to build prevention practitioners’ capacity to implement positive youth development-oriented prevention practices in 12 prevention coalitions in Maine. A survey of coalition members was used to assess change on individual practitioners’ prevention capacity between Baseline and one year later. Structured interviews with 32 program leaders (16 intervention, 16 control) were used to assess changes in prevention practices during the same time period. Change in prevention capacity over time between intervention and control did not differ, however in secondary analyses of only those assigned to the AGTO condition, AGTO users had evidenced greater improvement in their self-efficacy to conduct Assets-based programming and the frequency with which they engaged in AGTO behaviors. Non-users’ self-efficacy of AGTO declined. Interview ratings showed improvement in several key areas of performance among intervention programs. Improvement was associated with the number of technical assistance hours received. These results suggest that, after one year, AGTO is beginning to improve the capacity of community practitioners who make use of it.