LMIC stands for low- and middle-income country, a classification system created by the World Bank to group the world’s economies by wealth. About 85% of the global population lives in LMICs, making this designation central to discussions about global health, development aid, and economic policy. You’ll see the term frequently in news articles, academic research, and reports from organizations like the World Health Organization and United Nations.
How the World Bank Defines Income Groups
The World Bank divides every country into one of four income groups based on gross national income (GNI) per capita, which is essentially the average income generated per person in a country. The thresholds, updated every July, are adjusted for inflation so they reflect real purchasing power over time. For the current fiscal year (2026), the cutoffs in U.S. dollars are:
- Low income: $1,135 or less per capita
- Lower middle income: $1,136 to $4,495
- Upper middle income: $4,496 to $13,935
- High income: more than $13,935
When people say “LMIC,” they’re typically referring to the first three categories combined, though the term is sometimes used to mean only the lower-middle-income group specifically. Context usually makes the meaning clear. The classification aims to reflect a country’s overall level of development, using income as a broadly available indicator of economic capacity.
Which Countries Are LMICs
The low-income category includes many countries in sub-Saharan Africa and parts of South Asia, such as Ethiopia, the Democratic Republic of the Congo, and Afghanistan. Lower-middle-income countries include India, Nigeria, Kenya, and the Philippines. Upper-middle-income countries include Brazil, China, South Africa, and Mexico. China and India alone account for a massive share of the world’s LMIC population.
Countries can move between categories as their economies grow or contract. The World Bank recalculates classifications each year using the previous calendar year’s data, so a country experiencing rapid economic growth may “graduate” to a higher income group over time.
Why the Term Comes Up So Often in Health
LMIC appears constantly in global health research because income level shapes nearly every health outcome. Historically, infectious diseases like HIV, tuberculosis, and malaria have been the leading causes of illness and death in these countries, alongside malnutrition and complications during pregnancy and childbirth.
That picture is shifting. As economies develop and life expectancy rises, chronic conditions like hypertension, type 2 diabetes, cardiovascular disease, and cancer are becoming increasingly common in LMICs, particularly among younger populations. In countries like South Africa, China, and India, people now face a “double burden,” dealing with infectious diseases and chronic conditions simultaneously. Healthcare systems in most LMICs were built around treating one disease at a time through vertical programs, and the growing overlap of conditions is straining those systems.
HIV treatment is a telling example. Antiretroviral programs have dramatically extended life expectancy for people living with HIV, but longer lives mean higher rates of obesity, heart disease, and diabetes in the same populations, especially among women in economically disadvantaged areas. Managing multiple conditions at once requires a different kind of healthcare infrastructure than managing one.
The Research Gap
Despite being home to roughly 80% of the world’s population, LMICs are the site of only 43% of clinical trials for diseases that disproportionately affect their residents. That figure comes from the 2024 Access to Medicine Index, which analyzed 685 clinical trials. The imbalance is even more dramatic for the poorest countries: just 3.5% of clinical trials take place in low-income nations.
This matters for practical reasons. When a drug is tested almost exclusively in high-income countries, researchers may miss how it performs in populations with different genetics, diets, coexisting infections, or limited access to follow-up care. Treatments that work well in a controlled European hospital setting don’t always translate to a rural clinic with intermittent electricity. The gap also limits access to new medicines, since clinical trial participation is often one of the earliest ways patients in a country can receive cutting-edge treatments.
What LMIC Doesn’t Capture
The classification is useful but imperfect. A single national income average can mask enormous inequality within a country. Brazil and China are upper-middle-income countries, yet both have regions with poverty levels comparable to low-income nations. India, classified as lower middle income, contains both a booming tech sector and hundreds of millions of people living on very little.
GNI per capita also doesn’t reflect the cost of living, the quality of public services, or the strength of a country’s safety net. Two countries with identical GNI figures can have vastly different standards of living depending on how income is distributed and how much the government invests in healthcare, education, and infrastructure. Researchers and policymakers use the LMIC label as a starting point, not a complete picture.