Integrating distributed ledger technology (blockchain) into healthcare reimbursement and clinical data governance offers the potential to make operations more efficient, transparent, and trustworthy. However, focusing only on technical, regulatory, or behavioral factors in isolation often produces fragmented solutions and undermines adoption. This study develops a blockchain-based trust framework that bridges regulation with clinical practice by aligning auditability, data privacy, and clinician trust in automated reimbursement systems. The research combined a structured literature review with participatory action research, including three workshops with cross-functional health insurance teams, four focus groups (n=16) across health IT, compliance, legal, and patient services staff, and eight in-depth semi-structured interviews with healthcare executives. Thematic analysis, supported by substantial inter-coder agreement (κ=0.86), identified five determinants of trust—transparency, accountability, fairness, privacy, and usability. These insights informed the design of a reference architecture that integrates smart contracts, hybrid on-/off-chain data management, and interoperability through FHIR standards. A compliance mapping demonstrated that the framework addresses key provisions of GDPR, HIPAA, and Japan’s APPI, while the layered design separates policy, consent, and reimbursement logic. The resulting framework operationalizes stakeholder-defined trust requirements and provides auditable governance protocols suitable for cross-jurisdictional deployment. By embedding both trust and regulatory compliance into reimbursement automation, this work moves blockchain applications beyond proof-of-concept prototypes toward practical clinical integration. The framework contributes to biomedical informatics by offering a technically feasible, ethically grounded, and legally aligned pathway to enhance both reimbursement efficiency and data governance in healthcare environments.