Background: Primary care systems worldwide are under increasing strain due to workforce shortages, rising multimorbidity, aging populations, and escalating healthcare costs. Reconfiguration of professional roles—particularly between physicians and nurses—has emerged as a central strategy to maintain access, quality, and sustainability.

Objective: This review examines and contrasts the concepts of task redistribution and task substitution within primary care, with a focus on their implications for physician–nurse balance, patient safety, workforce dynamics, and health system performance.

Methods: A narrative review of international literature was conducted, synthesizing evidence from health services research, policy reports, and clinical studies addressing task allocation, nurse-led care models, and interprofessional practice in primary care.

Results: Task redistribution improves efficiency and continuity of care by reallocating defined activities within physician-led teams, while task substitution transfers autonomous clinical responsibilities to nurses, often advanced practice nurses. Both strategies demonstrate effectiveness when supported by appropriate training, governance, and regulatory frameworks. However, risks emerge when role boundaries, accountability, and escalation pathways are unclear.

Conclusion: Optimal primary care performance is achieved through a balanced, context-sensitive combination of task redistribution and selective task substitution. Policymakers and healthcare leaders should prioritize competency-based role design, interprofessional collaboration, and patient-centered governance rather than rigid professional demarcations.