'Middle-income countries (MICs)' are nations classified by the World Bank based on their gross national income (GNI) per capita. These countries fall between low-income and high-income thresholds and are further subdivided into:

• Lower-middle-income: GNI per capita between $1,136 and $4,465
• Upper-middle-income: GNI per capita between $4,466 and $13,845

This classification is updated annually and used widely in global health, economic development, and international policy.

• Rapid economic growth but with significant inequalities
• Dual burden of communicable diseases and non-communicable diseases
• Often in transition from donor aid to self-sustained systems
• Varied capacity in healthcare infrastructure, education, and governance

Middle-income countries are crucial in global health strategy because:

• They house a large portion of the world's population
• Many are sites for clinical trials, health system reforms, and surgical scale-up initiatives
• They often serve as models for scalable health interventions and policies

• Low- and Middle-Income Countries (LMICs)
• High-Income Countries (HICs)
• Global Health
• Health Systems
• World Bank Income Classification