There is growing evidence that long-term outcomes after traumatic brain injury (TBI) are more dynamic than stable. People continue to change, both improving and declining, many years post-injury. Research, practice and medical education have not yet fully embraced the implications of TBI as a chronic, dynamic condition. In 2020, the National Institute on Disability Independent Living and Rehabilitation Research funded the BeHEALTHY project to develop a model for long-term support of persons with chronic brain injury. Based on initial reviews of the available evidence and expert input from researchers, clinicians, and persons with lived experience, the BeHEALTHY model was proposed. Among existing chronic disease treatment models, Wagner's Chronic Care Model was selected as a starting point, with several critical refinements. The BeHEALTHY model endorses a person-centered approach, recognizing the individual with brain injury, and their social support system, as the primary source of goals in care planning. The model also acknowledges the critical importance of self-management and the need for healthcare programs to actively promote self-direction by the person using their social supports. The model also recognizes that outcomes are not determined solely by the person and the injury incurred, but also by the environment in which a person lives and recovers. The importance of integrating healthcare with community resources is underscored by embracing environmental influences as a shared responsibility of the community and the healthcare system. This article recounts the impetus for developing the BeHEALTHY model, and describes those it is intended to serve, structural features, and core components.