Abstract Obstructive sleep apnea (OSA) is a serious health condition that affects as many as 30-50% of older adults. OSA is associated with double the risk of cardiovascular disease and depression and as much as five times the risk for Alzheimer’s disease. These effects pose a real threat to healthy aging, not only for the OSA patient but also the bedpartner, as 61% of adults share a bed with a spouse/ partner. Despite the “shared” nature of OSA, treatments for OSA have nearly exclusively focused on the patient. Therefore, there is a critical need for interventions that address the impact of OSA and its treatment on both partners. Moreover, the first-line treatment for OSA, positive airway pressure (PAP), is highly effective but profoundly inadequate to reduce the health and societal costs of OSA, as >50% of patients are non-adherent. Couples-based adherence interventions, such as those used in other chronic health conditions, have been demonstrated to be more effective in improving patient adherence, and may have additional benefits for the partner and for the health of the couple. This R21 proposal aims to develop, refine, and test the preliminary efficacy of a novel couples’- based intervention (We-PAP) compared to a patient-focused information control group (IC). We-PAP is the first intervention which explicitly incorporates the partner into treatment (e.g. setting shared goals), and targets PAP adherence and overall sleep health of the couple as a whole. We-PAP is based on a transdiagnostic model designed to treat the shared components of multiple disorders rather than a single disorder. This treatment may be particularly important for older adults, patients and partners alike, due to increased risk for insomnia and other sleep disorders in this population. We hypothesize that addressing the treatment of OSA in the context of couples’ shared sleep experience will improve patient PAP adherence and the couples’ sleep health. In turn, we hypothesize that couples randomized to We-PAP will show measurable improvements in critically important outcomes in the context of aging, including clinically relevant cognitive outcomes, relationship quality, and QOL. Results of this R21 will be used to inform the design of a subsequent fully powered clinical trial of this novel intervention. Findings could significantly advance current clinical practice in the treatment of OSA and this intervention may be useful for improving sleep in other aging populations with multiple sleep disorders, including patients with or at risk for Alzheimer’s disease and their caregivers.