Project Summary We are proposing a revision to a current project, R01DK119282 entitled, “Mobile Phone Support for Adults and Support Persons to Live Well with Diabetes.” The current project includes an randomized controlled trial (RCT) to test the efficacy of the FAMS 2.0 (Family/friend Activation to Motivate Self-Care) intervention among N=334 adults with type 2 diabetes mellitus and a friend or family member who enrolls as a support person. The RCT includes a 9-month intervention period for those so assigned and 6-months of post-intervention follow up for a 15-month study. Recently, our team identified a typology of diabetes-specific family functioning which has important implications for intervention. We identified four conceptually distinct profiles of family functioning with respect to diabetes ("types") using cluster analysis and examined adjusted cross-sectional associations between type and diabetes outcomes. We found the typology was stable across analytic method and type was independently associated with diabetes outcomes, including glycemic control (primary outcome in the FAMS 2.0 RCT), diabetes distress (secondary outcome in the FAMS 2.0 RCT), diabetes self-efficacy and medication adherence (targeted mechanisms of the FAMS 2.0 intervention). The typology is the first ever to capture multiple dimensions of family functioning specific to diabetes self-management, is applicable across modern family structures, and has the potential to lead to breakthroughs in family interventions for adults with diabetes. Diabetes-specific family functioning type at baseline may be a critical and overlooked moderator of family interventions – including the FAMS 2.0 intervention – among adults with diabetes, and tailoring interventions to type may maximize effects. However, our prior typology study was conducted in a sample that was 75% White and used cross-sectional data. Therefore, we propose to expand the aims of the current R01 by conducting secondary data analysis and adding an exit interview for participants assigned to intervention. The aims of the current project will be unchanged and FAMS 2.0 will not be tailored to type in this RCT. For Aim 1 we will use data collected during the RCT to determine if the typology is replicated in a more diverse sample, examine type stability over time, and examine predictive validity of type for diabetes outcomes over time. For Aim 2, we will use mixed-methods to learn how engagement with and efficacy of the FAMS 2.0 intervention varies by type of diabetes-specific family functioning. Upon completion of these aims we will know how to identify persons with diabetes most likely to benefit from FAMS 2.0 to inform scalability and implementation efforts, and we will have preliminary data for a trial testing the benefit of tailoring interventions to participants' type of diabetes-specific family functioning. This research and future applications of the typology that will result from this research will rapidly advance t...