Background <p>Vocational rehabilitation (VR) interventions aimed at optimising job retention could help people with multiple sclerosis (MS) stay employed longer and prevent premature job loss. Currently, there is a lack of specialist services providing these types of interventions in the United Kingdom, and existing healthcare services are overstretched, hindering the introduction of a new service. This study aims to report on the adaptation of an MS-specific VR intervention for implementation within charities supporting those living with MS.</p> Methods <p>Semi-structured interviews with people with MS, employers, and employees from charities, and informal communication with stakeholders from national charities supporting employment for people with disabilities. This study used the ADAPT guidance and normalisation process theory (NPT), which together informed the design, stakeholder engagement, and data analysis using framework analysis.</p> Results <p>We conducted semi-structured interviews with 26 participants (11 people with MS, 12 MS charity employees, and three employers), and informal conversations with six stakeholders [charity employment specialists (<i>n</i> = 3), disability advisors (<i>n</i> = 2), charity CEO (<i>n</i> = 1)]. Four themes mapped to the core NPT constructs were identified to explain the implementation process, including service structure, training non-specialists, intervention components, and service promotion. Recommended adaptations include providing guidance on structured intervention sessions, collaborations with external organisations, and monitoring intervention delivery and performance to maximise the use of the limited resources available.</p> Conclusion <p>The adaptations identified can facilitate the delivery of the VR intervention within charities. Providing mentoring support, upskilling staff, and strategic collaborations are essential for the long-term sustainability of the intervention in this new context.</p>