This research aimed to map evidence about system supports and gaps for Australians with psychosocial disabilities and life-limiting diagnoses. A scoping review of available policy documents, academic, and grey literature was completed to discover key characteristics of this concept and provide context around the phenomenon. Our focus was on Australia’s National Disability Insurance Scheme (NDIS), a key reform providing support to the disability population nationally. No peer-reviewed or grey literature was retrieved on the phenomena. Therefore, three lines of enquiry were developed: experiences of NDIS participants living with psychosocial disabilities; the death, dying, and palliative care supports and experiences of NDIS participants of any disability type; and the experiences for people living with severe and persistent mental illness (SPMI) and life-limiting diagnoses. Five themes were identified: (1) the person; (2) advocacy; (3) informal supports; (4) formal supports; and (5) existing research. NDIS participants living with SPMI and their informal and formal support systems are still struggling to navigate the NDIS. While there are no specific publications about their end-of-life experiences, people with SPMI often experience poor end-of-life outcomes. Rigorous research into their death, dying, and palliative care experiences is needed to inform improved support to them, including their end-of-life care.