Thrive Mat-Su, an Alaskan community coalition working to prevent and reduce youth substance use, is expanding its strategies to reduce underage alcohol use in the Mat-Su Borough. Thrive Mat-Su will serve approximately 15,000 unduplicated individuals annually for a total of approximately 60,000 over the entire project period. Thrive's goals include increasing community collaboration and strengthening the coalition's capacity to prevent and reduce underage alcohol use as well as reducing alcohol use among youth ages 12-20. By June 29, 2020, Thrive Mat-Su will increase its membership across all sectors by 10%. By June 29, 2020, Thrive will train 20 coalition members in the Strategic Prevention Framework and Positive Culture Framework. By June 29, 2020, Thrive will collaborate with Cook Inlet TRibal Council on a shared initiative to prevent and reduce underage drinking and collaborate with Knik Tribal Council by the following year. By June 29. 2023, underage drinking (past 30 days use) will decrease by 10%, misperceptions about youth drinking behaviors will decrease 25%, youth perceptions of risk will increase by 25%, and perceived access to alcohol will decrease by 15%.