Pursuant to a congressional request, GAO reviewed federal and state efforts to provide services the individuals with traumatic brain injury (TBI), focusing on the: (1) primary federal and state programs that provide adults with TBI services to help them function more independently; (2) strategies that states have developed to enhance access to TBI-related services; and (3) circumstances believed to be most frequently associated with difficulty in obtaining services. GAO noted that: (1) adults with TBI receive services to facilitate their reintegration into the community primarily from three federal-state programs: Medicaid, vocational rehabilitation (VR), and Independent Living Services (ILS); (2) Medicaid provides medical, rehabilitation, and social support services to poor individuals with disabilities; (3) VR agencies provide services to individuals with disabilities to prepare them for and support them during the transition to employment; (4) ILS programs provide skills training to individuals with disabilities to facilitate their independence in the community; (5) all three programs are financed by a combination of federal and state funds and serve a range of individuals with disabilities, only a small number of whom have a TBI; (6) because most of the services covered by standard Medicaid programs are medical, all states have expanded Medicaid services through home and community-based waivers, which permit them to offer additional services–such as homemaker services, adult day care, and nonmedical transportation–to persons at risk of institutionalization; (7) these Medicaid waivers generally target long-term community-based services to a broad population, such as the physically disabled or disabled elderly; (8) recognizing the difficulties adults with TBI experience in accessing services, each of the states GAO contacted have developed various strategies to target services to adults with TBI; (9) five target Medicaid services specifically to limited numbers of adults with TBI; (10) despite these strategies, service gaps are likely–the number of adults with TBI who are provided services remains small relative to estimates of the total number; (11) according to program representatives and experts, those most likely to have difficulty accessing services are: (a) individuals with cognitive impairment but who lack physical disabilities; (b) individuals without an effective advocate to negotiate the social service system or without a social support system; and © individuals with problematic or unmanageable behaviors, such as aggression, destructiveness, or participation in illegal behaviors; and (12) without treatment, individuals with problematic or unmanageable behaviors are the most likely to become homeless, institutionalized in a mental facility, or imprisoned.