Establishing a viable program of care and support for people with severe brain injury is challenging for professionals and family members. The aims of this grounded theory study were to explore how decisions about care were made following brain injury when an individual had received third party compensation, and factors or conditions that influenced care. The sample (n = 51) included 14 people with traumatic brain injury (mean age 36.5 years, range 19–56; mean time post-injury 9.9 years, range 2.5–37), and 37 ‘others’, who either provided or coordinated care (12 family members, 14 paid carers, 6 case managers, 4 directors of care agencies and 1 estate manager). Data were collected using single interviews with each participant. All 14 people with brain injury had received 24-hour support at the time of hospital discharge; at follow-up, only 8 received 24-hour support. Care decision-making and care maintenance occurred as an iterative process. Participants made decisions about the best living situation, configuration of carers and level of care, and then strived to maintain stable care. Care decision-making involved three key strategies (gathering information, appraising alternatives, and enacting a decision). Care maintenance also involved three key strategies (monitoring, managing conflict and supporting carers). Mutual risk tolerance and the presence of a case manager were necessary conditions for good care management, and enabled a person with brain injury to spend time alone, take low-level risks and experience autonomy. Professionals and family carers can use the findings of this study to actively increase risk taking and autonomy.