Marital discord is a significant risk factor for a range of negative mental and physical health outcomes.1, 2 Individuals in unhappy relationships experience increases in stress, anxiety, functional impairment, and depressive symptoms3 and are at significant risk for substance abuse disorders.4-7 Furthermore, work loss associated with marital problems translates into a deficit of approximately $6.8 billion per year for U.S. businesses and industry due to absenteeism, reduction in productivity, and increased healthcare costs.8 Couple Relationship Education and Skills Training (CREST) is an effective approach for preventing and reducing marital discord and its associated problems.9, 10 Unlike couple therapy, which focuses on resolving marital conflict and involves regular sessions with a trained therapist,10 CREST provides proactive education and skills training as a preventive and early intervention approach to improving relationship quality and stability.11 CREST curricula provide skills training targeting specific cognitive (knowledge, attitudes), affective, and behavioral constructs shown to be efficacious in promoting stable relationships.9, 10, 12 The proposed project will develop a comprehensive online CREST resource based on the extant research evidence (e.g., meta-analyses of CREST programs)9, 10, 13 for the prevention and reduction of couple conflict and its associated problems. The innovation of this online CREST program is in the technology, which moves beyond simply presenting text and online forms to incorporating current best practices in technology and adult e-Learning (web and mobile delivery; Behavioral Modeling Training using scenario- based instructional design with interactive skill-building activities; action planning; behavioral tracking). In the proposed Phase2 development, CREST will be integrated with the ORCAS parenting skills programs (R44 DA15563, R44 DA12082 and R43 DA016830).14 The product will be designed for use in Employee Assistance Programs (EAPs) as (a) a preventive standalone program to promote relationship quality and stability among couples proactively seeking to do so, and (b) a skills-building program used by EAP counselors as an adjunct to couple therapy. In Phase 2, the full-scope CREST program will be developed and evaluated in a large-scale randomized trial.