Abstract The vision of the USC-Yale Roybal Center for Behavioral Interventions in Aging is to expand the reach of effective behavioral interventions that address the over- and underuse of medical care through an understanding of their mechanisms of behavior change. The specific aims of the Center are to: (1) improve the general effectiveness of behavioral interventions that address over- and underuse of health services in aging populations by clarifying their mechanisms; (2) address crucial problems relating to translation and development of physician and patient interventions that facilitate value-based health care decisions, and (3) test up to 10 randomized trials that evaluate mechanisms of behavior change. Our Center will operate under the NIH Stage Model for behavioral interventions creating a pipeline of studies that span from basic research (Stage 0) through full-scale dissemination of interventions (Stage V). Work will be managed through an Administrative Core and research is conducted through a Behavioral Interventions Development Core. The Center has a diverse External Advisory Committee composed of experts in behavioral science, mechanisms of behavior change and health system leaders. Health system leaders work at implementation sites who will recommend the priorities for studying mechanisms of behavior change. Implementation site members are expected to broker relationships with their own institution so that these institutions can be test-bed for trials evaluated by the committee. We propose two randomized trials in the first year of the award. The first study aims to reduce potentially inappropriate prescribing in older adults who visit the emergency department. The second study aims to encourage older adults to designate a healthcare proxy. Both studies are Stage III and involve randomization. Pathways toward advancing the stages of these two projects are discussed as are solicitations for new trials in out-years. Continuity with the prior Roybal award is reflected in the Center’s focus on greatest potential for population health impact through improvements in medical decisions. Through its health system partners, the Center also expands its ability to support a growing community of researchers conducting behavioral interventions to encourage appropriate use of medical treatments for midlife and elderly populations.