Complete List of NIH Institutes and Centers

The National Institutes of Health comprises 27 institutes and centers, each with a distinct scientific mission, dedicated budget line, and administrative structure operating under the Office of the NIH Director. Understanding the full roster — including how institutes differ from centers, how funding authority is distributed, and which components focus on disease-specific versus cross-cutting research — is essential for grant applicants, researchers, clinicians, and policy analysts who work within the federal biomedical enterprise. This page provides a structured breakdown of all 27 components, the organizational logic that separates institutes from centers, and the practical boundaries that determine which component leads a given research program.

Definition and Scope

The NIH is a component of the U.S. Department of Health and Human Services and serves as the primary federal agency for biomedical and behavioral research (NIH, nih.gov). Its 27 institutes and centers are individually authorized by Congress and, in most cases, carry their own appropriations. The distinction between an institute and a center is structural and functional, not merely nominal.

• Institutes (20 total) are typically organized around a disease category, organ system, or population group. Each has extramural grant-making authority, intramural research laboratories, and a presidentially appointed director.
• Centers (7 total) are generally cross-cutting in function. They support NIH-wide programs — such as scientific review, research resources, complementary and integrative health, or minority health — rather than focusing on a single disease domain.

For context on how these components fit within the broader administrative hierarchy, see the NIH Organizational Structure page.

How It Works

Each institute and center receives a discrete appropriation through the annual Labor, Health and Human Services, and Education appropriations bill. In fiscal year 2023, NIH's total appropriation was approximately $47.5 billion (NIH Office of Budget, officeofbudget.od.nih.gov). That budget is distributed across all 27 components, with allocations varying dramatically — the National Cancer Institute (NCI) consistently ranks as the largest single recipient, while smaller centers such as the John E. Fogarty International Center operate on budgets roughly 1% of NCI's annual level.

The NIH Director's Office coordinates cross-component priorities, but each institute director retains authority over intramural programs, extramural grant portfolios, and internal strategic planning. The NIH Director Role and Leadership page details how that governance relationship functions.

Common Scenarios

The 27 NIH Institutes and Centers

Institutes (20)

1. National Heart, Lung, and Blood Institute (NHLBI) — see the National Heart, Lung, and Blood Institute overview
2. National Institute on Aging (NIA) — see the National Institute on Aging overview
3. National Institute of Allergy and Infectious Diseases (NIAID) — see the NIAID overview
4. National Institute of Mental Health (NIMH) — see the NIMH overview

Centers (7)

1. Center for Scientific Review (CSR) — the primary intake and peer review hub for NIH grant applications; see the NIH Peer Review Process page for operational detail
2. National Library of Medicine (NLM) — operator of PubMed and MedlinePlus; see NIH PubMed and Research Databases
3. NIH Clinical Center (CC) — the world's largest hospital dedicated exclusively to clinical research; see the NIH Clinical Center page

This list reflects the structure documented by NIH as of the agency's official institute and center roster (NIH Office of the Director, nih.gov/institutes-nih).

Decision Boundaries

Several practical distinctions matter when navigating the NIH component structure.

Institute vs. Center for Grant Applications

Grant applicants do not typically choose which institute funds their award — that determination is made during assignment by the Center for Scientific Review based on scientific scope and mission alignment. An application studying infectious disease mechanisms will route to NIAID; one addressing aging-related neurodegeneration may route to NIA or NINDS depending on the primary focus. Applicants can request assignment, but CSR retains final authority. The NIH Grant Application Process page explains the assignment procedure in detail.

Disease-Specific vs. Cross-Cutting Institutes

NCI, NIMH, NIAID, and NHLBI each maintain large, disease-focused extramural portfolios and independent intramural campuses. NIGMS and NCATS, by contrast, fund foundational science and translational infrastructure that serves the full research ecosystem rather than any single disease category. Researchers pursuing basic biochemistry or cell biology often find NIGMS the relevant primary funder, while those advancing a therapy toward clinical application may engage NCATS programs such as the Clinical and Translational Science Awards (CTSA) network.

Intramural vs. Extramural Programs

Not every institute maintains an equivalent intramural presence. NIEHS operates its primary intramural campus in Research Triangle Park, North Carolina — geographically separated from the main Bethesda campus. The NIH Intramural vs. Extramural Research page addresses how funding, employment, and publication rules differ across these two research tracks.

For a broader orientation to the full scope of the agency's activities, the NIH home reference provides a structured entry point across all major topic areas covered in this resource.

Funding Concentration

The top 5 institutes by appropriation — NCI, NIAID, NHLBI, NIDDK, and NIMH — collectively account for more than 50% of the NIH budget in a typical fiscal year (NIH Office of Budget). The remaining 22 components divide the balance, which explains the substantial variation in grant portfolio size, review timeline, and programmatic initiative activity across components.