During this phase, the procurers move from planning to implementation. The selected contractors execute the R&D or deployment activities defined in the PCP or PPI, under close monitoring and evaluation. The procurers ensure contractual compliance, technical progress, and result validation across all phases of the procurement. This phase generates concrete innovations, validated solutions, and lessons learned to inform future policy and practice. This phase divides into two main implementation pathways: one for PCP and one for PPI. Both start with the contracting and monitoring setup (IV.A), ensuring that the selected suppliers and teams are formally established and ready to execute. The PCP pathway then progresses through three stages (IV.B.1–IV.B.3), each deepening the development, validation, and refinement of innovative solutions, while PPI activities (IV.B.4) focus on co-deployment and process validation. Research protocols and ethics approvals (IV.C.1) run in parallel with the validation and deployment stages (IV.B.2–IV.B.4), providing continuous oversight and compliance. Payor engagement, outcome assessment, and adoption planning (IV.C.2) are specific to the PPI route and take place after completion of IV.B.4. In addition, innovators follow a mirrored sequence (IV.D.1–IV.D.4), aligning design, testing, and implementation activities with the procurers’ roadmap.