Background: Adults ageing with a disability need lifelong access to health services to meet their changing needs. This study aimed to explore in depth the experience and impact of health service access to address mobility change in adults ageing with cerebral palsy (CP). Method: Semistructured interviews were conducted. Qualitative analysis and identification of themes were undertaken on resultant transcripts. Results: Six community-living adults (35-52 years) with CP, at levels II and III of the Gross Motor Function Classification System -- Extended & Revised (GMFCS-E&R), participated. All described adult-onset mobility decline and had experienced recent falls. Emergent themes explored the accessibility, nature, and type of health service available, comparisons to paediatric experience, and themes related to frustration, perceived control, and self-advocacy. Conclusion: Adults with CP report variability in the access to and matching of health service provided with self-perceptions of service type and need to address mobility decline. Adults with CP describe frustration regarding their experiences and may seek opportunities to increase self-advocacy regarding available health and support services.