During public health crises like the COVID-19 pandemic, and recent measles, hantavirus, and Ebola outbreaks, the Centers for Disease Control and Prevention (CDC) has served as a face of the federal government's public health response. As of 2025, CDC describes its core mission as "protecting Americans from infectious and non-communicable diseases and investing in innovation to prevent, detect, and respond to such public health threats." CDC works to prevent most of the leading causes of death, injury, and disability, and also promotes health more generally. CDC is based in the Department of Health and Human Services (HHS) and is a U.S. Public Health Service (PHS) agency. The CDC Director also oversees the Agency for Toxic Substances and Disease Registry (ATSDR), a separate operating division. For further information, see CRS Report R47981, Centers for Disease Control and Prevention (CDC): History, Overview of Domestic Programs, and Selected Issues.
CDC began as the Communicable Disease Center in 1946, focused on assisting states and localities in controlling communicable disease outbreaks. CDC's role expanded over the decades to include programs aimed at disease prevention and health promotion more broadly. In 1980, when CDC was renamed the Centers for Disease Control (after two prior name changes), its official mission was to serve as HHS's "focus for developing and applying disease prevention and control, environmental health, and health promotion and health education activities designed to improve the health of the people of the United States." In 1992 Congress recognized CDC's expanded mission in disease prevention and codified CDC's current name (P.L. 102-531). Throughout the 20th century, CDC evolved along with an epidemiologic transition, where the leading causes of death in the United States shifted from infectious diseases to chronic diseases and injuries. CDC also evolved as public health experts and scientists identified the preventable causes of a wide range of health challenges.
CDC focuses on supporting science-based disease prevention and health promotion on a population-wide basis. CDC is organized into 23 centers, institutes, and offices (CIOs), some focused on public health challenges (e.g., immunization and respiratory diseases; injury prevention), while others focus on public health capabilities (e.g., surveillance and laboratory services).
CDC CIOs administer programs focused on a range of health topics, including infectious diseases, chronic diseases, injury, disability, occupational health, maternal health, birth defects, environmental health, and public health emergency preparedness. Even with the range of topics, a few key functions are common across programs:
Support for Public Health Infrastructure. CDC provides leadership and coordination in public health across the country and around the world, including assistance in investigating and responding to health threats. In the United States, many public health laws and programs are administered at the state, local, territorial, and tribal (SLTT) levels. CDC provides funding, workforce, and technical support to SLTT public health agencies. CDC's global programs seek to support public health throughout the world through direct relationships with health agencies in other countries and participation in multilateral initiatives.
CDC awards grants to SLTT health agencies and other partners. In FY2023 (most recent data), CDC awarded 6,982 grants, totaling over $12.6 billion in obligations, including $6.7 billion in non-COVID related awards and $5.8 billion in COVID-related awards (mostly funded by supplemental appropriations). Recipients included SLTT governments, nonprofit organizations, foreign governments and international organizations, for-profit organizations, and tribal entities. Most of the grant funds were awarded to domestic government entities (70%), and state government agencies accounted for 85.4% of these funds. Some grants, such as the Immunization Cooperative Agreement program and the Preventive Health and Health Services Block Grant program, provide public health funding to all states, territories, and selected local jurisdictions. Others provide funding on a competitive basis to a subset of SLTT agencies. CDC administers many of its grant programs with SLTT agencies as cooperative agreement programs, where CDC staff have substantial involvement in program implementation and evaluation.
CDC also funds SLTT-based programs to provide preventive health services, such as vaccinations and cancer screenings, targeted at uninsured and underserved populations. For example, CDC administers the Medicaid-financed Vaccines for Children program (VFC), for which CDC purchases childhood vaccines at a discounted rate and distributes them to states, territories, and certain localities to allow participating providers to furnish them at no cost to eligible children. According to a study of young children, roughly 52.2% of such children are eligible for VFC.
Science and Data. CDC conducts and funds research and investigation into health challenges, generally with a focus on how they can be prevented and controlled. Many CDC research articles are published in the agency's Morbidity and Mortality Weekly Report, in addition to other agency journals. CDC also awards research grants and contracts to universities and other research institutions. CDC-supported research and science inform its other programs, such as the public health interventions implemented in grant programs or its health education and guidance.
To facilitate science, CDC administers many health data programs. CDC uses the data in its own research and makes data available to outside researchers and the general public. CDC's data collection programs generally fall into two categories: surveillance systems and surveys. Public health surveillance is "the ongoing, systematic collection, analysis, and interpretation of health-related data essential to planning, implementation, and evaluation of public health practice." CDC operates over 100 surveillance systems that collect ongoing data. CDC often receives surveillance data from SLTT health agencies and global partners, usually based on voluntary data sharing agreements. CDC's National Center for Health Statistics also administers several national health surveys, like the National Health Interview Survey, known as the "principal source of health information" on the U.S. civilian population. These data help inform an understanding of when, how, where, and to which populations disease cases and other health events occur, as well as about the overall health of the population.
CDC also manages federal laboratories that can perform specialized testing to detect new or unusual health threats. CDC also oversees the Laboratory Response Network (LRN), a network of laboratories at the federal, state, and local level that can detect biological, chemical, and other threats, including emerging infectious diseases. CDC develops laboratory test kits, protocols, and best practices, and distributes test kits and supplies to LRN and other U.S. and global public health laboratories. Several grants can also support public health laboratory operations and testing.
Health Education and Guidance. Health education is a component of almost all of CDC's programs. CDC conducts education and outreach to many audiences, including the general public, clinicians, and public health practitioners. CDC also regularly develops guidelines educational materials for public health partners and health care providers, including some clinical practice guidelines. In addition, CDC informs the science and practice of public health communication.
CDC administers some regulations, though it is not primarily a regulatory agency. These include regulations related to the medical examination of immigrants and refugees, possession and use of select biological agents and toxins, occupational health, and interstate and foreign regulations for the control of communicable diseases known as its quarantine regulations. Among other provisions, CDC's quarantine regulations include rules aimed at preventing the spread of infectious diseases from imported materials, including from human remains, certain animals, and infectious biological materials.
The statutory basis for CDC and its programs is complex. Since its inception, CDC has been shaped in large part by administrative actions that established the agency and then reorganized and added programs. Congress has funded the agency's organizational changes through annual appropriations laws. Throughout this time, Congress also enacted authorizations for specific organizational units, programs, activities, and regulatory authorities within CDC.
Congress has not uniformly established specific authorizing statutes for all of CDC programs. As a result, since its inception, CDC has relied on the Public Health Service Act's (PHSA's) general public health authorities for many of its programs, including those related to research and investigation (PHSA §301; 42 U.S.C. §241), international cooperation (PHSA §307; 42 U.S.C. §242l), health conferences and education (PHSA §310; 42 U.S.C. §242o), federal-state cooperation in public health (PHSA §311; 42 U.S.C. §243); and preventive health grants (PHSA §317; 42 U.S.C. §247b). The PHSA, first enacted in 1944 (P.L. 78-410), authorizes many HHS public health functions.
In 2022, the PREVENT Pandemics Act (P.L. 117-328; Division FF, Title II) codified the position of the CDC Director at PHSA Section 305 (42 U.S.C. §242c). The provision directs the Director to perform several functions, including implementing relevant PHSA authorities and responsibilities related to the prevention or control of diseases or conditions; preserving and improving public health domestically and globally; and addressing injuries and occupational and environmental hazards.
Congress shapes CDC's programs through annual appropriations. In FY2026, CDC has an estimated total program funding level of $16.3 billion, consisting of roughly $9.2 billion for its core public health programs and an estimated $7.7 billion for programs funded by mandatory budget authorities such as the VFC program. Congress has historically directed CDC's funding toward certain disease topics and programs through annual appropriations reports that were not specifically incorporated by reference in law but to which agencies, by practice, were generally expected to adhere. In FY2026 (P.L. 119-75, Division B), a new Section 236 incorporates certain CDC funding levels included in the appropriations report by law, which includes over 140 budget lines.
CDC has historically received supplemental appropriations in response to public health emergencies and other incidents. For example, as of April 30, 2024, CDC directly received $25.2 billion in supplemental funding for COVID-19 response and also administered over $40 billion on behalf of the HHS Office of the Secretary. For more information see CRS Report R47207, Centers for Disease Control and Prevention (CDC) Funding Overview.
Recently, policymakers have debated CDC's mission. In FY2026 and FY2027 budget requests, the Trump Administration proposed to streamline CDC to focus on a "core mission" of infectious disease and health threat response. Congress did not adopt this proposal for FY2026. Some public health stakeholders have argued that CDC's focus across health areas reflects the broader public health field and does not warrant change. Aside from disease topics, Congress might view CDC in terms of its functions (e.g., science and data, education) and roles (e.g., outbreak response, health promotion) to determine the appropriate mission for the agency. In 2025, Senate Republicans launched a working group on CDC reform. No bills to comprehensively reform CDC have been introduced in the 119th Congress.