Prisoners With intellectual and developmental disability (IDD) experience health inequities, potentially compounded by issues of acquiescence, misunderstanding, and social isolation. On release, ex-prisoners with IDD may be ‘pushed’ between operational silos and receive little or no transitional support to address factors shown to increase the risk of recidivism,such as substance use[1].Following their release, ‘mainstream’ ex-prisoners experience greatly elevated risk of death from overdose[2]and infectious disease transmission through unsafe needle and injecting equipment use.Few data are available about post-release substance use or mortality among ex-prisoners with IDD, despite soon-to-be-released prisoners with IDD reporting similar patterns of normative substance use compared to their peers without disability [3]. Cognitive and sensory differences may render support of and service delivery to this highly vulnerable population group particularly challenging; whether administered within disability, justice or health systems, and ideally across all three