Treatment research with AI/AN is in its infancy. One route to address the substantial substance use related health disparities is to employ evidence-based treatments (EBTs) with AI/AN. EBTs are rarely tested with sufficiently large samples of racial ethnic groups, so outcomes are often unknown. Recently, an R01 DA021672 adapted two EBTs for substance use disorders (SUDs) (motivational interviewing and community reinforcement approach - MICRA) and conducted a randomized controlled trial (RCT) to MICRA to treatment as usual with the same AI community as involved in this proposal. The present study seeks to expand on that R01, which culturally tailored CRA for people with SUDs, but now turn our focus to working with families and concerned significant others (CSOs) who want to help engage their loved one with an addiction (identified person; IP) into treatment. The intervention, Community Reinforcement and Family Training (CRAFT), is built on reinforcement principles. CRAFT teaches CSOs to take better care of themselves, to cease any behaviors that are not working to address the IP's substance use, and to consistently reward the IP for any sober and treatment engagement behavior. Importantly, CRAFT has been shown to increase IP entry into treatment, which would address: (1) the high rates of SUDs and related problems among AI/AN, (2) low rates of AI/AN self-referrals to treatment, and (3) higher rates of AI entering treatment due to court mandates. The present study aims to conduct an RCT to compare an AI culturally adapted version of CRAFT (CRAFT-AI; n=20) to Twelve-step facilitation for CSO's (TSF-CSO) using principles and groups of Nar/Al-Anon (n=20) to examine acceptability of a culturally tailored EBT and estimate effect sizes for IP treatment entry and for CSO functioning pre to post intervention. Notably, this will be the first examination of potential mediators and moderators of CRAFT-AI including variables such as: demographic variables, severity of SUD, self-efficacy, and cultural risk and protective factors. Finally, we will examine the appropriateness of broadening the dependent variable of IPs entering formal treatment to include AI traditional healing. The methodology of this grant using a partnership between academic and tribal researchers is well-poised to contribute to nascent AI/AN SUD treatment research to impact the substantial health disparities AI/ANs and other indigenous populations endure. Positive study results will facilitate future cultural adaptation research and dissemination and diffusion of EBTs to interested AI/AN tribes and other culturally diverse populations.