Purpose: The present study aimed to quantify the perceived needs and adequacy of realised access to post-acute services in a sample of people with acquired brain injury in the first 6-months after discharge from inpatient rehabilitation. A secondary focus was the influence of access to funding and specialist transitional rehabilitation on unmet needs. Materials and methods: Participants were 51 adults with a median age of 50 (IQR 35–57) recruited from an inpatient rehabilitation unit in an Australian tertiary hospital. The sample was those who had an acquired brain injury, including 23 who sustained a traumatic injury and 28 who sustained a non-traumatic injury. Measures were collected via telephone at 3- and 6-months, in a prospective observational cohort design using the Needs and Provisions Complexity Scale. A series of logistic regression models were used to determine the effects of participation in a transitional rehabilitation program and funding pathway on adequacy and unmet needs. Results: Unmet needs for rehabilitation were most commonly reported (60%), followed by unmet needs in relation to health care (40%), social care (35%), personal care (32%) and environment-related (14%). Participants who attended transitional rehabilitation were more likely to indicate unmet health care needs (OR = 6.40, 95% CI = 1.40–29.24, p = 0.02). Conclusions: The study highlights the need to look beyond functional impairment when conceptualising appropriate access. Additionally, the present research highlighted the need for greater work into an expectation of services.IMPLICATIONS FOR REHABILITATION The majority of people with an acquired brain injury report unmet needs at 6 months post discharge. Present findings support the utility of patient reported measures when considering treatment evaluation with people with ABI, where assessing the personal appraisal of individuals needs may prove to be a key indicator to facilitate optimal service access. There are specific services that needed and not provided including psychological, speech pathology, family carer needs and vocational rehabilitation, and therefore are a key target for ensuring appropriate support is provided.