An integrated evidence generation plan (IEGP) builds on the clinical development plan to demonstrate the broader value of a therapy to healthcare professionals, patients, caregivers, HTA bodies, payers and policymakers. Medical Affairs is uniquely positioned to lead because it combines scientific and clinical expertise with an external, patient- and access-focused perspective. Four Medical subfunctions have distinct roles: Medical Strategy aligns evidence priorities to product strategy; Evidence Generation and HEOR design studies that address comparative, economic and patient-relevant questions; Medical Communications aligns evidence and dissemination planning early; and Field Medical brings real-world stakeholder questions into the plan. The IEGP should begin by phase II protocol development or earlier where appropriate, remain dynamic as the environment changes, and be measured from outputs to outcomes to long-term impact on patient experience, access and outcomes.