Background:This study sought to obtain an in-depth understanding of autistic transgender and/or non-binary adults' experiences in accessing, or trying to access, gender identity health care (GIH). To our knowledge, no prior study researched this topic.Methods:Through semi-structured interviews, we obtained the first-hand experiences of 17 participants. H.B. (cisgender, non-autistic) conducted a reflexive thematic analysis using an inductive approach, in collaboration with K.M., an autistic transgender disability community researcher, and under the supervision of S.K.K., a cisgender autistic autism researcher.Results:Thematic analysis determined that poor knowledge of professionals, accessibility issues, and bureaucratic and economic barriers impacted participants' experiences when accessing GIH. Participants experienced a perceived lack of professional knowledge around autism and gender diverse health care needs, limited communication methods and accommodations, and misdiagnosis of mental health difficulties. Accessibility issues included unmet sensory needs, disruption to routine, and a lack of local provision. Further, participants shared that they struggled with unclear processes, standardization of care, long waiting lists, and confusing or inaccessible insurance coverage. Recommendations for improvements highlighted the need to listen to service users to positively impact their experiences in accessing GIH.Conclusion:This study suggests that more training needs to be given to health care providers and professionals around autistic experience to help improve providers' competence in communication and providing person-centered accommodations. More training around gender diverse identities is needed, as well as increased knowledge on the co-occurrence of autism and transgender/non-binary identities, to positively impact patient experiences and help improve access to care.