The fragmented nature of healthcare systems typically leads to inefficiencies in patient care coordination, particularly when individuals transition between providers. This paper proposes a blockchain-based framework to address the challenge of decentralized medical record and billing management. By assigning patients a unique blockchain public address, health-care providers can securely access historical treatment data, prescriptions, and billing information through a tamper-proof, patient-authorized ledger. The system employs smart contracts to automate access permissions, ensuring only verified providers retrieve encrypted records after obtaining patient consent. Cryptographic techniques, such as asymmetric encryption, safeguard sensitive data while enabling interoperability across disparate healthcare networks. A hybrid architecture combines on-chain metadata (e.g., transaction hashes, timestamps) with off-chain storage of encrypted records through distributed file systems, balancing scalability and security. The solution minimizes administrative redundancies, reduces billing disputes, and mitigates risks of incomplete medical histories. Case study simulations demonstrate a 40% reduction in duplicate diagnostic tests and a 30% improvement in billing accuracy compared to traditional electronic health record (EHR) systems. By prioritizing patient-centric data ownership and regulatory compliance, such as HIPAA and GDPR, this framework enhances care continuity, fosters trust among stakeholders, and establishes a scalable model for secure health information exchange.