A cancer diagnosis requires patients and their intimate partners to communicate effectively to navigate illness- related challenges. Research indicates that couples who use effective communication strategies have better individual psychological adjustment and higher relationship satisfaction. However, many couples have difficulty communicating about cancer-related issues which can lead to poorer individual, relationship, and patient health outcomes. While dyadic interventions to improve couple communication have proven efficacious, they are often time intensive and have limited reach. The challenges of recruiting couples into dyadic interventions are well-documented, with low recruitment rates especially among underserved couples. Micro-interventions, which consist of brief educational materials and short activities delivered via text message or a mobile application, have significant potential to increase reach and participation in diverse groups of couples by increasing flexibility and reducing barriers to access. Previous studies have found micro-interventions to be effective in promoting health behavior change in a wide range of individuals and in enhancing dyadic functioning in community couples. To date, there are no existing micro-interventions that have been developed and tested in couples coping with cancer. Therefore, the proposed project aims to develop, and pilot test a text-messaging micro-intervention focused on improving communication skills for couples coping with advanced gastrointestinal (GI) cancer. The content of the dyadic micro-intervention will be adapted from existing, empirically validated couple-based interventions developed for cancer and non-cancer couples. Aim 1 focuses on developing the micro-intervention through focus groups and interviews with couples coping with advanced GI cancer and community advisors representative of minority groups, along with user experience testing with the target population. The data collected will be used to increase content relevance, acceptability, feasibility, and cultural sensitivity of the micro-intervention. Aim 2 will be a randomized pilot test of the dyadic micro-intervention to assess feasibility and acceptability. Aim 3 will examine pre-to-post intervention outcomes as measured by improvements in relationship satisfaction and constructive communication. This project is in line with the National Cancer Institute’s priority research area of cancer survivorship and has the potential to increase health equity in cancer by increasing participation of underserved couples. The proposed project will provide training in 5 key areas for the applicant: (1) psycho-oncology and cancer control, (2) theories and didactics related to the development, implementation, and dissemination of behavioral interventions in the context of cancer, (3) mixed research methods specific to development of psychosocial interventions, (4) health equity, diversity, and inclusion training, and (5) professional deve...