Introduction Manual wheelchair training is essential for safe and independent wheelchair use; however access remains inconsistent and poorly aligned with the needs of individuals who commence wheelchair use later in life. This program of research aimed to understand what works, for whom, and under what circumstances, to inform practical guidance to improve equity, safety, independence, participation and broader health outcomes for older people with chronic and progressive conditions. Methods A critical realist approach was used to explore how and why manual wheelchair training works for older adults with chronic and progressive conditions. Insights from practice knowledge, literature and interviews with wheelchair users and trainers informed program-theories and actionable recommendations, which were prioritised through stakeholder consultations. Results Effective training supports motivation, confidence, autonomy and self-efficacy, while accommodating variability in physical capacity, cognition and readiness to engage. It builds strength-based relationships with trainers, peers and care partners, fostering psychological safety, trust and enables observational learning, supporting engagement and skill acquisition. Organisational capacity, continuity of care and intentional training design ensure access to training that is responsive to individual needs and goals. When delivered in meaningful environments, training supports problem solving and skill transfer. At a policy level, frameworks embedding funding, governance and accountability enable consistent access and improved participation outcomes. Conclusion These findings provide actionable recommendations to improve equity, safety and continuity of manual wheelchair training. Achieving this requires coordinated, system level reform with aligned funding, governance and accountability, alongside investment in workforce development to support training across contexts and over time.