The Coronavirus Disease 2019 (COVID-19) pandemic shined a spotlight on the Centers for Disease Control and Prevention (CDC), one of nine Public Health Service (PHS) agencies in the Department of Health and Human Services (HHS). CDC's role in and response to the pandemic have been the subject of numerous congressional hearings and oversight investigations.

With CDC the nation's lead agency for disease prevention and health promotion, CDC's primary domestic activities include providing support to state, local, tribal, and territorial (SLTT) health agencies, which are often at the forefront of public health. CDC also supports public health research, investigation, and data collection and provides public health education, guidance, and outreach to various audiences, including the general public, clinicians, and public health practitioners. These activities cover a wide range of health topics, including infectious diseases, chronic diseases, injury, disability, occupational health, environmental health, and public health emergency preparedness and response. In addition, the agency exercises regulatory authority in a few limited areas, such as in federal quarantine and inspection and occupational health and safety. CDC also administers a few health services programs, such as the Vaccine for Children program. Through its global health programs, CDC provides public health assistance to foreign governments (these activities are not a focus of this report).

Initially established in 1946 as a small center focused on controlling malaria and other vector-borne diseases, CDC evolved into the federal government's lead agency for disease prevention and health promotion in 1980. The agency grew through acquisition when many other preexisting federal public health programs, such as programs for tuberculosis and vital statistics, were transferred to CDC. In addition, Congress shaped CDC by enacting legislation aimed at strengthening its programs in certain areas, such as in injury prevention and control and public health emergency preparedness and response. Throughout CDC's history, CDC Directors have undertaken comprehensive reviews of the agency that informed subsequent reorganizations, for example in the late 1970s and most recently through the Moving Forward initiative, which began in 2022.¹

All of this occurred against the backdrop of changing health concerns and a growing health prevention science field. Throughout the 20^th century, an epidemiologic transition occurred in which the leading causes of death in the United States shifted from mostly infectious diseases to mostly chronic diseases and injuries. Epidemiologists adapted the methods developed for controlling communicable diseases to learn the preventable causes of a wide range of diseases and health problems. At the beginning of the 20^th century, most diseases were viewed as a matter of fate. By the end of the 20^th century, it was widely understood that many health problems could be prevented, whether through vaccines, bug spray, seatbelts, helmets, condoms, diet, exercise, or other measures. CDC positioned itself to study how to prevent health problems and to support prevention and control programs to address such challenges.²

During the 118^th Congress, some Members of Congress have contemplated legislative reform of CDC following the agency's perceived performance during the COVID-19 pandemic.³ In particular, CDC has received scrutiny for its development and distribution of an initial laboratory test for COVID-19, as well as for its COVID-19 related health guidance, which critics perceived as confusing or favorable to certain interest groups.⁴ Some have asserted that CDC has lost public trust, citing polls showing declining favorable public views of CDC and other public health agencies.⁵ One independent investigative report characterized CDC's culture as academic and slow to respond to the urgent and changing emergency health situation posed by the pandemic.⁶ CDC has acknowledged some of these challenges in its own internal Moving Forward evaluation, and has since begun an internal reform process.⁷

There are many current views and proposals regarding potential CDC reform. Some have called for Congress to formally authorize CDC in statute.⁸ Although Congress shapes CDC's funded programs through appropriations each year, CDC does not currently have a single, overarching statute that defines the agency's mission, structure, and programs. As Representative Guthrie, chair of House Energy and Commerce Health Subcommittee (committee of jurisdiction for CDC) put it, "Congress has never, in a single voice, told the CDC what its mission is and is not."⁹ Others have called for Congress to establish a more formal process for considering potential CDC reform, for example, by establishing an external advisory group to evaluate the agency and propose reforms.¹⁰ Still others have called for patience, arguing that Congress should allow CDC to continue with its Moving Forward reform effort before considering any major legislative reform.¹¹

This CRS report (1) provides an overview of CDC and presents selected issues for potential legislative reform; (2) describes CDC's history and contextualizes its evolution into the agency it is today, including a discussion of Congress's role in that evolution; and (3) outlines the CDC's current mission, organization, statutory authorizations, appropriations, and major domestic programs and activities. Information on the Agency for Toxic Substances and Disease Registry (ATSDR)—a separate HHS operating division authorized by Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA)—is included within the overall discussion of CDC programs.¹² This CRS report does not focus on CDC's international programs and activities.

History and Context

Brief History

The public health system in the United States grew out of the sanitary reform movement of the 19^th century, which was premised on the view that disease was caused by environmental conditions and lack of sanitation.¹³ Throughout the 1800s, states and cities established Boards of Health, often with broad powers to protect their residents' health.¹⁴ These boards generally focused on tackling potential sources of disease in the physical environment. They conducted surveys on the health conditions of their populations, performed inspections, investigated outbreaks, and disinfected possessions and locations thought to cause disease. By the end of the 19^th century, 40 of the 45 states then in existence and many localities had established health departments. In the late 19^th century, as scientific understanding of the germ theory of disease developed, many of these health departments established laboratories to identify and investigate the germs that caused disease. State and local public health agencies then expanded their roles, moving into surveillance (i.e., disease data reporting and monitoring), clinical care, and health education.¹⁵

Some trace the federal government's role in public health to the Marine Hospital Service (MHS), a system of federally run hospitals for merchant seamen first established in 1798.¹⁶ By the late 1800s the MHS began to play a role in preventing the introduction and spread of infectious diseases into the United States by ship—including smallpox, yellow fever, and cholera. In 1878, Congress enacted the first federal quarantine law to prevent and control the introduction of infectious diseases into the United States.¹⁷ The MHS's role then expanded to include public health activities, for example, federal quarantine, vaccination efforts, epidemic investigations, and medical examinations of immigrants.¹⁸ MHS was renamed the Public Health and Marine Hospital Service in 1902 and then the Public Health Service in 1912.¹⁹

Public Health Service Act of 1944

Even before CDC existed, Congress enacted the Public Health Service Act of 1944 (PHSA), which established the general set of federal public health authorities that, as amended, remain the basis of many CDC programs and regulations today.²⁰ The PHSA consolidated and revised all preexisting federal laws pertaining to the U.S. Public Health Service (PHS), which had become part of the Federal Security Agency.²¹

As explained below in the "Statutory Authorizations" section, Title III of PHSA established a general set of federal public health authorities, including the authority to engage in research and investigations, to regularly publish health statistics and reports, and to assist states in preventing and controlling diseases.²² PHSA Title III also established the federal legal authorities for foreign and interstate quarantine and isolation to control communicable diseases. At the outset, the Surgeon General envisioned the federal government's role in public health as focused primarily on assisting the states with implementation of their public health programs. According to the statement of the Surgeon General, then head of the PHS, after its enactment

[T]he new law will facilitate the smooth operation of the Federal-State public health programs and will make it possible to expand State and local health services to the people. With a minimum of Federal administrative control to insure efficient and economical expenditure of Federal funds, State health authorities develop, organize, and administer their own programs; but on technical problems, planning and administration of comprehensive programs, and training of personnel they look to the Public Health Service for leadership and expert advice. ²³

1946-1950: Establishment and Initial Years

The modern-day CDC began as the Communicable Disease Center in 1946.²⁴ The center grew out of the Office of Malaria Control in War Areas (MCWA), which had been established in 1942 to prevent and control the spread of malaria around military training centers in the U.S. South.²⁵ MCWA had been headquartered in Atlanta, GA, and CDC has been headquartered there since. By 1946, most of the military training centers had closed, but federal officials saw value in maintaining the expertise and capabilities of the office to prevent and control communicable diseases in the United States more generally.²⁶ CDC was established administratively within the U.S. Public Health Service. Congress subsequently provided an appropriation in support of the new center.²⁷

Initially, CDC was focused on vector-borne communicable diseases such as malaria.²⁸ (Vector-borne diseases are caused by "vectors" such as mosquitoes, ticks, and fleas.²⁹) In the following years, CDC's role expanded to assist states in addressing other outbreaks and health threats, including diarrheal diseases and polio.³⁰ By 1949, the center had become a division of the Bureau of State Services within the PHS and had the following responsibilities:

This center … provides through the regional offices to State and local health agencies consultation and training in the development and operation of communicable disease control programs and public health laboratory practices. It plans, directs and evaluates in cooperation with State and local health agencies programs for the control of selected communicable disease; provides professional leadership, and makes available the latest professional techniques in connection therewith. The center conducts and evaluates studies and investigations in the development of new and improved procedural techniques for the prevention, detection, diagnosis, control and treatment of communicable disease, and enforces the medical aspects of the interstate quarantine regulations. ³¹

1950s-1960s: Expansion in Epidemiology, Communicable Disease, and Vaccination Programs

In its early years, CDC became known for the Epidemic Intelligence Service (EIS), which was established in 1951 to respond to the threat of potential biological warfare.³² EIS remains a core CDC program today.³³ In the early 1950s, EIS was composed of early-career medical professionals who were trained by CDC to use epidemiology to control communicable diseases. Epidemiology uses statistical methods to study how often diseases occur in specific groups of people and to help trace the factors that contribute to disease. Epidemiology commonly relies on surveillance, or systematic and ongoing disease tracking and analysis. After training, EIS officers were available on-call to assist states with controlling communicable disease outbreaks. From the beginning, CDC received frequent requests for EIS assistance and the center became known for its ability to use applied epidemiology to help control disease spread.³⁴

Reorganization Plan No. 1 of 1953 dissolved the Federal Security Agency and established the Department of Health, Education, and Welfare (HEW) in its stead (see textbox below). CDC was transferred to the new department. Throughout the early decades of its existence, CDC absorbed other programs and divisions within the PHS, for example, the Venereal Disease Division in 1957, the Tuberculosis program in 1960, the Morbidity and Mortality Weekly Report in 1961, and the Quarantine Service in 1967.³⁵ As the Venereal Disease Division was absorbed into CDC, along with it came the public health advisors (PHAs), a cadre of early career health workers assigned to states who investigated sexually transmitted disease (STD) cases (then known as venereal disease). These young professionals implemented mass testing programs, interviewed patients, and traced patients' contacts—functions that remain core parts of public health programs today.³⁶

In 1955, CDC responded to its first national health crisis. After the Salk polio vaccine became available, the PHS began to receive reports of polio cases among children who received the vaccine. CDC established a surveillance unit to monitor and investigate the cases and provide regular summaries of findings to state health officers and others involved in disease control. CDC eventually learned that 80% of the reported cases were associated with one product that constituted 10% of the total vaccine supply. A manufacturing issue was found and the product was pulled from the market. This incident, often called "the Cutter incident" (attributed to vaccine producer Cutter Laboratories), set a precedent for CDC to take a leadership role in national response during future emerging health threats and outbreaks, especially by leading national disease tracking and surveillance.³⁷ CDC subsequently played a similar role in coordinating U.S. national disease tracking during the 1957-1958 Asian influenza pandemic, which caused several U.S. outbreaks.³⁸

In the 1960s, CDC began to play a key role in federal immunization programs. Following the licensure of the Sabin oral polio vaccine in 1961, Congress enacted the Vaccination Assistance Act of 1962,³⁹ which established the first federal grant program focused on several immunizations.⁴⁰ The law added a new PHSA Section 317, which authorized a state grant program for intensive community vaccination programs against polio, diphtheria, whooping cough, and tetanus—a program that remains in place today and is commonly known as the "Section 317 Immunization Program."⁴¹ CDC became responsible for administering the new grant program. The agency provided funding and vaccines to states, and PHAs helped with program implementation. As the measles and rubella vaccines were licensed in 1963 and 1969, respectively, the two types of vaccines were integrated into the program. Incidence of vaccine-preventable disease fell throughout the 1960s.⁴²

In the late 1950s, CDC began to provide public health assistance to other countries. At first, CDC provided periodic assistance during disease outbreaks. During the global Asian influenza pandemic in 1957-1958, CDC helped distribute testing supplies throughout the world, informed global laboratory practices, and tracked and summarized disease cases.⁴³ In 1966, an international malaria eradication program was transferred from the Agency for International Development to CDC. CDC's international work subsequently expanded to include a smallpox eradication program and a famine relief initiative.⁴⁴

CDC was briefly renamed the National Communicable Disease Center in 1967.⁴⁵ By 1968, it became a center within the broader Health Services and Mental Health Administration agency. Its responsibilities were to support "a national program for the prevention and control of communicable and other preventable diseases."⁴⁶

1970s: Becoming the Center for Disease Control and Expanding Scope

In 1970, CDC was renamed the Center for Disease Control. CDC's official responsibilities had widened to encompass "a national program for the prevention and control of communicable and vector-borne diseases and other preventable conditions, including those related to malnutrition."⁴⁷ At the time, CDC's program areas consisted of (1) ecological investigations, (2) epidemiology, (3) foreign quarantine, (4) malaria, (5) nutrition, (6) small pox eradication, (6) training, (7) laboratory, and (8) state and community services (including those related to tuberculosis, other respiratory diseases, and STDs).⁴⁸ This marked the first time that CDC's official responsibilities included noncommunicable health conditions. However, even before this change—as early as the 1950s—the CDC Director had assigned staff to study the epidemiology of noncommunicable health issues, such as cancer, malnutrition, and family planning.⁴⁹

By the end of 1973, after a series of PHS reorganizations, CDC officially became one of the service's six main agencies (instead of a division within a larger program).⁵⁰ Throughout the 1970s, the scope of CDC's work expanded as the agency established programs in the areas of nutrition, environmental health (e.g., lead exposure), smoking tobacco and health, occupational safety and health, oral health, cancer, health education, family planning, and birth defects.⁵¹ CDC acquired the PHS nutrition survey in 1971 (today known as the National Health and Nutrition Examination Survey, NHANES), the National Clearinghouse on Smoking and Health in 1972, and the National Institute for Occupational Safety and Health, along with lead paint poisoning prevention and urban rat control programs, in 1973.⁵²

During the 1970s, CDC was credited with some public health successes. With assistance from CDC's global smallpox program, which relied on a strategy of surveillance and containment, smallpox was announced officially eradicated from the globe in 1979.⁵³ By the end of the decade, the last human case of wild poliovirus (rather than vaccine-induced) was reported in the United States. Using NHANES data, CDC's environmental services division helped determine that blood lead levels were associated with lead concentration in gasoline, which led to regulations that decreased the amount of lead in gasoline and subsequently reduced blood lead levels in the population.⁵⁴

CDC also faced scrutiny in the 1970s. In 1972, CDC was criticized for the so-called Tuskegee study begun in 1932 that left untreated syphilis in Black male patients for decades, even when treatment became available, in order to study progression of the disease. The agency had inherited the study with the transfer of the Venereal Diseases Division in 1957.⁵⁵ CDC was also criticized for taking years to determine the cause of Legionnaires' disease, a severe form of pneumonia that caused several deadly outbreaks at the time. In addition, a 1976 mass immunization campaign to protect against a potential swine flu epidemic was suspended early when no influenza outbreak occurred and the vaccines were found to be associated with a rare but increased risk of Guillain-Barre syndrome, a severe neurological disorder.⁵⁶ A subsequent review at the government's request found that the "program was marked by controversy, delay, administrative troubles, legal complications, unforeseen side effects and a progressive loss of credibility for public health authorities," and the review implicated the CDC Director in many of the challenges faced.⁵⁷ Some have since defended the CDC Director's decisions, arguing that he made the right decisions based on available information.⁵⁸

1980s: The Centers for Disease Control, Lead Disease Prevention Agency, and the HIV/AIDS Epidemic

In the late 1970s, CDC Director William Foege sought to shape CDC's future direction by soliciting public input and convening an advisory committee of outside experts and members of the public.⁵⁹ The committee published a report in 1978 that identified the highest priority preventable health problems at the time, recommended strategies to address those problems, and made recommendations regarding CDC's role. The report recommended that CDC become the lead federal agency for disease prevention to address the full range of health problems facing the nation and the globe.⁶⁰

The following year, the Surgeon General, with input from CDC, published the first Healthy People report, which laid out the major preventable health challenges facing the country and marked a national commitment to prevention.⁶¹ This report also set the stage for CDC to take a holistic approach to disease prevention and health promotion in the 1980s.

The Department of Education Organization Act,⁶² enacted in 1979, created the Department of Education as a separate department and renamed the Department of Health, Education, and Welfare as the Department of Health and Human Services. The following year, CDC was reorganized and renamed the Centers for Disease Control (with the "s" added) and its official mission (which remains in place today) became as follows:

The Centers for Disease Control (CDC) serves as the Department'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. ⁶³

At the time, CDC consisted of programs and offices focused on (1) epidemiology, (2) biosafety, (3) international health, (4) laboratory improvement, (5) prevention services, (6) environmental health, (7) occupational safety and health, (8) health promotion and education, (9) professional development and training, and (10) infectious diseases.⁶⁴ The key new additions included the Center for Health Promotion and Education and Center for Environmental Health, both of which incorporated preexisting CDC programs.⁶⁵

Most prominently, the 1980s were marked by the HIV/AIDS epidemic.⁶⁶ CDC first received reports of the new disease in 1981 and then conducted further epidemiologic and laboratory investigations. CDC quickly learned that the disease spread primarily among men who had sex with men and was likely caused by a blood-borne virus. CDC formed a taskforce on the disease and warned that it could become a major health issue.⁶⁷

Budgetary constraints of the early 1980s limited CDC's ability to direct resources to the problem.⁶⁸ By the mid to late 1980s, as the disease spread more widely, Congress had begun to dedicate more resources to HIV/AIDS programs. CDC's HIV prevention budget grew from $200 thousand in FY1981 to over $300 million in FY1988 (not inflation adjusted).⁶⁹ CDC used its established methods of assessing risks and developing preventive programs in its efforts to control the epidemic. Throughout the 1980s, CDC established several new grant programs to fund HIV/AIDS prevention and control programs at the state and local level and spearheaded several informational campaigns on the disease.⁷⁰ By FY1991, HIV/AIDS funding represented 37% of the agency's budget.⁷¹

1992-Present: Centers for Disease Control and Prevention

The Preventive Health Amendments of 1992 changed all statutory references to CDC in law to "Centers for Disease Control and Prevention," the name of the agency today.⁷² Since the early 1990s, CDC's programs have continued to evolve. As shown in the textbox above, discussions about the appropriate role and scope of public health in the late 1980s and early 1990s set the stage for issues on which CDC would focus in the following decades. This section discusses some of the agency's major areas of focus.

Vaccines for Children and other immunization programs. Following a measles epidemic from 1989 to 1991, where half of all cases occurred among unvaccinated preschool children, the Omnibus Budget Reconciliation Act of 1993⁷³ established the Vaccines for Children (VFC) program in Section 1928 of the Social Security Act.⁷⁴ Through this Medicaid-financed program, CDC purchases recommended childhood vaccines in bulk at a federally negotiated discounted rate and distributes them to SLTT agencies to allow participating providers to furnish them at no cost to eligible children (see the "Vaccines for Children" section). Together with the long-standing PHSA Section 317 immunization program (see the "1950s-1960s" section), the VFC program helped expand CDC's role in supporting the infrastructure for immunization safety-net programs across the country. Starting in the 1990s, CDC also began to expand other immunization programs; for example, it invested in the nation's network of Immunization Information Systems, population-based data systems that help record and track immunizations received.⁷⁵

Chronic disease. Since the 1990s, CDC's chronic disease prevention and control programs have expanded. In the early 1990s, Congress enacted several laws authorizing cancer programs at CDC. For example, in 1992, Congress enacted the Cancer Registries Amendment Act,⁷⁶ which established the National Program of Cancer Registries—state-based systems to collect and track data on cancer.⁷⁷ In addition, in 1990, Congress enacted the Breast and Cervical Cancer Mortality Prevention Act of 1990,⁷⁸ which established a CDC state grant program to fund cancer screening among uninsured and underinsured women, the National Breast and Cervical Cancer Early Detection Program (NBCCEDP). More recently, starting in 2008, CDC also funded heart disease and stroke risk factor screenings for the population served by NBCCEDP, known as the WISEWOMAN program.⁷⁹ In FY2023, CDC's Chronic Disease Prevention and Health Promotion program funded about 30 separate grant programs for state and local governments.⁸⁰

Firearm injury and mortality prevention research and the "Dickey amendment": In the mid-1990's, some concerns arose surrounding perceived political biases of CDC research related to firearms and violence.⁸¹ Starting in FY1997, Congress added a new appropriations limitation that, at the time read, "none of the funds made available for injury prevention and control at the Centers for Disease Control and Prevention may be used to advocate or promote gun control."⁸² A version of this amendment, commonly known as the "Dickey amendment," has been included in annual appropriations every year since FY1997.⁸³ While the language does not specifically mention research, CDC responded to the amendment and the surrounding political controversy by limiting its research related to firearms and violence.⁸⁴ Some studies have found that since the limitation has been in effect, firearm-related violence has been underfunded and understudied relative to other leading causes of death based on mortality rates.⁸⁵

Starting in FY2020 (P.L. 116-94), following several high-profile mass shootings, Congress has provided $12.5 million annually to CDC for "firearm injury and mortality prevention research." These amounts have been directed in appropriations report language for each of FY2020 through FY2023.⁸⁶ During a 2019 House Appropriations subcommittee hearing, some Members of both parties expressed support for keeping the Dickey amendment in place as a "guardrail," while funding CDC research related to firearms and violence.⁸⁷

Public health emergency and bioterrorism. In 1999, CDC established several new major public health emergency programs. For example, CDC launched the National Pharmaceutical Stockpile, now known as the Strategic National Stockpile (SNS), a federal stockpile of drugs, vaccines, and other medical products intended for emergency responses (SNS is now housed at the Administration for Strategic Preparedness and Response).⁸⁸ In the same year, CDC established the Laboratory Response Network, a coordinated network of laboratories at the federal, state, and local level with specialized capabilities to detect biological, chemical, and other health threats.⁸⁹

As discussed in greater detail in the "Example 3: Public Health Emergency Activities" section, Congress has enacted a series of statutes since 2000 that have likewise expanded CDC's role and programs in public health emergency management and response.

Major infectious disease outbreaks and epidemics. Since the early 2000s, CDC has responded to several major global and domestic infectious disease outbreaks. These have included the severe acute respiratory syndrome outbreak (SARS; 2003), H5N1 avian influenza (2005), H1N1 pandemic influenza (2009), Ebola virus (2014-2015 and 2018-present), Zika virus (2016), the Coronavirus Disease 2019 pandemic (COVID-19; 2020-2023), and mpox outbreak (2022). In particular, concerns about a potential avian influenza pandemic in 2005 prompted many congressional hearings, plans, and policy assessments on national preparedness for a pandemic that informed CDC's subsequent responses.⁹⁰ Many of these infectious disease responses—especially the COVID-19 pandemic—have tested CDC's role as a lead public health agency with expertise in infectious disease control and response, as explained further in the next section.

The Affordable Care Act and public health programs. The Patient Protection and Affordable Care Act (ACA⁹¹), enacted in 2010, was landmark health policy legislation that made many changes across federal health policy areas, including public health prevention and health promotion programs. The ACA authorized several new programs at CDC and codified several existing programs, including programs related to infectious diseases, diabetes prevention, and oral health.⁹²

The ACA established a new mandatory budget authority for public health, the Prevention and Public Health Fund, "to provide for expanded and sustained national investment in prevention and public health programs to improve health and help restrain the rate of growth in private and public sector health care costs."⁹³ That ACA section has appropriated funding annually, and as directed through annual appropriations, CDC has received the majority of this funding in recent years (e.g., $903 million to CDC in FY2023 out of $943 million total). This PPHF, combined with annual discretionary appropriations, serves as one of CDC's main sources of budget authority for public health programs.⁹⁴

Current Status: The COVID-19 Pandemic and CDC's Moving Forward Initiative

During the COVID-19 pandemic, CDC took a highly visible role in educating the public about the virus and disease, collecting and tracking COVID-19 data, informing COVID-19 research and science, and issuing health guidance aimed at prevention and control. CDC also advised and coordinated many national public health programs, for example, testing, contact tracing, and vaccination efforts.⁹⁵ The agency also used its regulatory authorities to issue public health orders during the pandemic, for example, an order requiring vaccination for international travelers to the United States and an order restricting the entry of certain noncitizens into the United States, commonly known as the "Title 42" entry restrictions.⁹⁶

CDC and its actions during the pandemic have been the subject of numerous congressional hearings, oversight reports, and independent evaluations. In particular, CDC received scrutiny for its development and distribution of an initial laboratory test for COVID-19, as well as for its COVID-19 related health guidance, which critics perceived as confusing or favorable to certain interest groups.⁹⁷ Some have asserted that CDC has lost public trust, citing polls showing declining favorable public views of the agency.⁹⁸ One independent investigative report characterized CDC's culture as academic and slow to respond to the urgent and changing emergency health situation posed by the pandemic.⁹⁹ Some have argued that the challenges CDC faced during the pandemic are attributable to a general lack of funding and capacity at CDC and, more broadly, in the public health system.¹⁰⁰

In April 2022, CDC's leadership began a review and reform process, entitled Moving Forward, aimed at modernizing the agency to better achieve its mission. The initial review consisted of two components: a scientific and programmatic review and an organizational structure review. Broadly, the structural review found that CDC's academic approach sometimes hindered its ability to rapidly respond to an evolving threat such as the COVID-19 pandemic. In particular, the review found that the agency's incentive structures rewarded scientific publications over impact and actions. The review also found that the agency could benefit from becoming more flexible and less siloed by health area or program.¹⁰¹ In February 2023, CDC finalized an agency reorganization following recommendations from the evaluations (see the "Organization" section for more details).¹⁰² The agency stated that, as a result of the initiative, it was working through 160 reform actions targeted to be completed by January 2024. These included, for example, website changes, laboratory capacity reforms, CDC-wide response training, and data modernization.¹⁰³

Figure 1. CDC Organizational History: A Timeline

Source: See the sources in the "History and Context" section of this report.

CDC's Evolution in Context

As shown in CDC's organizational history in Figure 1, the scope of the agency has greatly expanded since it was first established. CDC evolved and grew as an agency as the fields of public health and prevention science grew. In the first half of the 20^th century, a greater scientific understanding of the germ theory of disease helped facilitate the communicable disease control science and methods for which CDC became known.¹⁰⁴ CDC cultivated specialized expertise within the federal government in disease control, specifically in the developing fields of epidemiology and surveillance.¹⁰⁵

Throughout the 20^th century, the field of public health became more specialized, and distinguished itself from the field of medicine. Public health grew to encompass research into the social, environmental, and biological determinants of health, broadly, along with the practice of addressing those determinants.¹⁰⁶ The 20^th century also saw a shift in the burden—or overall health impact—of diseases. In the early 1900s, infectious diseases were the major causes of death in the United States. By midcentury—including by the time CDC was established in 1946—chronic conditions such as cancer and heart disease became the leading causes of death (often called the epidemiologic transition). Throughout the 20^th century, even after 1946, mortality rates from infectious diseases fell, except during epidemics such as the HIV/AIDS epidemic and the COVID-19 pandemic. ¹⁰⁷ As the major health concerns changed, so too did the field of public health and its focus areas. ¹⁰⁸

In particular, evolution in the field of epidemiology—in which CDC cultivated distinct expertise—helped expand the scope of public health.¹⁰⁹ Throughout the 20^th century, epidemiologists learned to apply the scientific methods developed for communicable diseases to a wide range of diseases and conditions, including chronic diseases and injuries. Epidemiologists helped scientifically determine the risk factors that led to poor health; for example, the scientific relationships between smoking tobacco and lung cancer, folic acid intake and birth defects, and seat belt use and motor vehicle fatalities.¹¹⁰ This scientific understanding could then be used to develop public health interventions to address risk factors, such as health education and promotion campaigns.¹¹¹ CDC was in a position to support both the data collection and research into risk factors, as well as some of the programmatic interventions to address them.

Within this context, CDC expanded in scope as an agency. As recounted in the brief history here, CDC sometimes expanded through acquiring existing programs and through departmental reorganizations. CDC fit these diverse programs under the broad umbrella of public health such that by the 1980 reorganization, CDC became HHS's focus for developing and applying disease prevention and control and for promoting health more broadly.¹¹² The 1980 reorganization was also preceded by a broader reassessment of CDC's role in addressing preventable health challenges. In addition, as illustrated in the next section, Congress has at times facilitated new or enhanced programs and roles for CDC through both the authorizations and the appropriations process.

Congress's Role in Shaping CDC

As noted above, CDC has been substantially shaped by a series of administrative reorganizations throughout the 20^th century. Congress has also played a role in shaping the agency. Much of this role has been to provide the agency with annual appropriations, often through disease- or program-specific accounts and budget lines, that have shaped CDC's programmatic focus areas.¹¹³ In addition, Congress has at times enacted authorizing legislation aimed at shaping CDC's programs and functions. Examples of each of these methods of shaping CDC are included below. Most recently, Congress formally authorized the position of the CDC Director and required agency-wide strategic planning through the PREVENT Pandemics Act.¹¹⁴

Appropriations

Congress has provided annual appropriations for CDC programs since the agency was first established (see the "1946-1950: Establishment and Initial Years" section). Through this process, Congress has often appropriated funding based on certain health or program areas. Earlier in its history, the entire U.S. Public Health Service received appropriations for specific public health functions; the appropriations laws did not specify the specific operating divisions or units to carry out such activities. For example, in the appropriations act for FY1960,¹¹⁵ the Public Health Service received appropriations for "Assistance to States," "Control of Venereal Diseases," "Control of Tuberculosis and Communicable Disease Activities," among other purposes.

In 1974, after CDC became one of five main PHS agencies, appropriations laws began to appropriate funds to CDC more directly.¹¹⁶ In recent decades, Congress has appropriated funds to specific accounts within CDC aligned with certain broad health areas (e.g., immunization) or activity areas (e.g., epidemic services). Within these accounts, Congress often specifies funding for particular programs through appropriations report language (see Figure 2). The number and specificity of CDC's programmatic budget lines within accounts have grown over the past several decades. To illustrate, in FY1990, the conference report accompanying CDC appropriations specified funding levels for 18 programs within CDC accounts.¹¹⁷ In FY2023, the explanatory statement accompanying CDC appropriations specified funding levels for more than 140 line-items within CDC accounts (in both accompanying tables and text).¹¹⁸

Figure 2. How Congress Shapes CDC Programs Through Appropriations: Illustrative Example

Source: CRS analysis of CDC appropriations.

Authorizing Legislation: Case Studies

At times, Congress has enacted legislation that has created new programs or changed CDC's authorities and functions. Three illustrative examples are explained in the following case studies. In the first example (injury prevention and control), Congress authorized a specific type of activity at CDC. In the second example (the National Center on Birth Defects and Developmental Disabilities), Congress explicitly established a new center at CDC by statute. In the third example (public health emergency activities), Congress established and shaped CDC's roles and programs in public health emergency preparedness and response through a series of laws that have been periodically reauthorized since 2000.

Example 1: Injury Prevention and Control

A 1985 report requested by Congress, Injury in America: A Continuing Public Health Problem, called for addressing injuries—including traffic-related injuries, falls, drowning, poisoning, violence, and other injuries—as public health problems, including by increasing research into the causes of injuries and the means to prevent them. The report recommended that a Center for Injury Control be established within CDC.¹¹⁹ Congress then enacted the Injury Prevention Act of 1986,¹²⁰ which formally authorized CDC injury prevention and control activities in the Public Health Service Act.¹²¹ CDC's budget for injury prevention and control grew from $10 million in 1985 to $49.2 million in 1997 (not inflation adjusted). CDC established the National Center for Injury Prevention and Control in 1992.¹²²

Example 2: National Center on Birth Defects and Developmental Disabilities

The Children's Health Act of 2000¹²³ amended the PHSA to establish, in statute, the National Center on Birth Defects and Developmental Disabilities (NCBDDD) within CDC.¹²⁴ According to CDC, the center was created in response to "strong advocacy efforts by external organizations whose view was that children's health issues were not being adequately addressed by CDC."¹²⁵ In 2001, CDC moved the staff and resources of the preexisting Division of Birth Defects and Developmental Disabilities out of the National Center for Environmental Health, where it had been located for over 30 years, to become the new NCBDDD.¹²⁶

Example 3: Public Health Emergency Activities

Beginning in 2000, Congress enacted a series of laws aimed at strengthening public health emergency capabilities within CDC and other HHS agencies. The Public Health Threats and Emergencies Act, enacted in 2000, included several provisions that required assessments of national public health emergency capacity and needs.¹²⁷ The law also authorized grants to support state and local capacity to address health threats. In addition, the law authorized CDC to improve its laboratories and other facilities to support public health emergency capacity. It included a section that stated,

Congress finds that the Centers for Disease Control and Prevention have an essential role in defending against and combatting public health threats of the 21^st century and requires secure and modern facilities that are sufficient to enable such Centers to conduct this important mission.¹²⁸

The committee report accompanying the Senate bill expressed concern that many state and local health departments would not be able to rapidly and effectively respond to a major outbreak in their communities. The report also noted that federal agencies, such as CDC, needed updated laboratories, facilities, and technologies for public health emergency response. In particular, many buildings at CDC had not been updated since just after World War II, and many of CDC's laboratories lacked capabilities required for research with dangerous infectious agents.¹²⁹

Following the 9/11 terrorist attacks and the anthrax incident of 2001, Congress enacted the Public Health Security and Bioterrorism Preparedness and Response Act of 2002,¹³⁰ which sought to further enhance public health emergency capacity. The law enhanced CDC's authorities to improve its laboratory facilities and surveillance networks to respond to public health threats. The law also authorized CDC's Public Health Emergency Preparedness (PHEP) cooperative agreement program in PHSA Section 319C-1, a grant program that funds public health emergency preparedness and response capacity in state and local health departments. This law set the stage for the Pandemic and All Hazards Preparedness Act of 2006 (PAHPA),¹³¹ which reauthorized and further amended the CDC provisions enacted in 2002. PAHPA has since been reauthorized twice, in 2013¹³² and 2019,¹³³ and both times included additional provisions that addressed CDC programs related to public health threats.

The programs authorized by these laws have helped develop the field of public health emergency preparedness and response across the country. CDC has established 15 foundational capabilities that SLTT health agencies should have in order to prevent, protect against, respond to, and recover from public health emergencies such as infectious disease outbreaks and chemical, biological, nuclear, and radiological threats.¹³⁴ These include functions such as emergency coordination, public health laboratory testing, and medical countermeasure (e.g., vaccines, treatments) dispensing and administration. SLTT health agencies are required to invest in these capabilities as a condition of receiving CDC PHEP grants. These programs have brought frameworks from the emergency management field into public health responses to various health threats, such as infectious diseases. Much of the evolution in the field of public health emergency management was driven by legislation enacted by Congress.¹³⁵

Agency Overview Today

The following sections provide an overview of CDC as an agency today, including its mission, organization, authorizations, funding, and key activities.

Mission

Like several other agencies established by executive action, CDC does not have an overall mission or purpose defined in statute. In 2022, Congress articulated the breadth of the agency's work in the PREVENT Pandemics Act.¹³⁶ The act codified the position of the CDC Director and provided that the Director is to implement responsibilities and authorities that are

related to the investigation, detection, identification, prevention, or control of diseases or conditions to preserve and improve public health domestically and globally and address injuries and occupational and environmental hazards, as appropriate.¹³⁷

As established in Federal Register notices, CDC's official mission statement is as follows:¹³⁸

The Centers for Disease Control and Prevention (CDC) serves as the national 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 addition, CDC's stated mission on its website is as follows:

CDC works 24/7 to protect America from health, safety and security threats, both foreign and in the U.S. Whether diseases start at home or abroad, are chronic or acute, curable or preventable, human error or deliberate attack, CDC fights disease and supports communities and citizens to do the same.

CDC increases the health security of our nation. As the nation's health protection agency, CDC saves lives and protects people from health threats. To accomplish our mission, CDC conducts critical science and provides health information that protects our nation against expensive and dangerous health threats, and responds when these arise.¹³⁹

CDC's mission statements comprise two predominant themes. First, the agency is responsible for overall health promotion and disease prevention. Second, the agency is responsible for health security and response to specific health threats.

Organization

As shown in Figure 3, CDC is organized into many centers, institutes, and offices (CIOs). Some of these CIOs focus on specific public health challenges (e.g., injury prevention and control), while others focus on general public health capabilities (e.g., state, tribal, local, and territorial public health infrastructure and workforce).

Figure 3. CDC Organization Chart

Source: Adapted by CRS from CDC, "CDC Organization Chart," https://www.cdc.gov/about/pdf/organization/cdc-org-chart.pdf, updated as of February 23, 2023. Notes: HIV = Human Immunodeficiency Virus; STD = Sexually Transmitted Disease; TB = Tuberculosis.

CDC most recently underwent a reorganization in 2023 as a part of its Moving Forward initiative.¹⁴⁰ According to CDC, the reorganization was informed by feedback from staff and partners on how CDC could change its structure to better respond to public health challenges. The reorganization included the following key changes:¹⁴¹

• CDC created the new National Center for State, Tribal, Local, and Territorial Public Health Infrastructure and Workforce, intended to improve collaboration with local health departments and public health partners.
• To align with its "core capabilities," CDC established new offices within the Office of the Director: the Office of Health Equity; the Office of Public Health Data, Surveillance, and Technology; the Office of Laboratory Science and Safety; and the Office of Readiness and Response.

Statutory Authorizations

As discussed above, CDC is an administratively established agency that has been shaped by congressional appropriations and some program authorization statutes. Congress has mostly shaped CDC's programs through specifying and directing funding through the annual appropriations process. The agency, like several other agencies established by executive action, does not have a single, overarching statute that defines its overall mission, structure, or programs.¹⁴² CDC's programs are authorized by general and program-specific laws, mostly in the PHSA. The position of the CDC Director and its responsibilities were codified into law in December 2022.¹⁴³

CDC Director Authorization

Authorized in PHSA Section 305,¹⁴⁴ added in December 2022, the CDC Director is responsible for the overall direction of CDC and the Agency for Toxic Substances and Disease Registry, as well as the management and operation of its programs.¹⁴⁵ This law made the CDC Director a presidentially appointed and Senate-confirmed position, effective January 20, 2025. The authorization does not define the specific programs for which the CDC Director is responsible; instead, the law defines the general scope of the Director's authorities and responsibilities (see the "Mission" section).

PHSA Section 305 also requires the CDC Director to develop a strategic plan every four years to identify overall priorities and objectives for the agency.

General Program Authorizations

The general public health authorities of the Public Health Service Act, many of which were established in 1944, have long underpinned CDC's activities (see the "Public Health Service Act of 1944" section). CDC's current programs and structure evolved from a series of reorganizations and acquisitions, as discussed in the "Brief History" section. Many CDC programs across a wide range of health areas cite general and permanent PHSA Title III authorities of the HHS Secretary as their statutory basis, including the following:

PHSA Section 301 (42 U.S.C. §241): Research and Investigation. This section allows PHS agencies, including CDC and the National Institutes of Health (NIH), to conduct, coordinate, and fund research and investigations "relating to the causes, diagnosis, treatment, control, and prevention of physical and mental diseases and impairments of man." Under this authorization, PHS agencies may award grants and contracts for research, publish studies and research-based health information, and make available PHS facilities for research, among other research activities. CDC cites PHSA Section 301 as one authorizing statute for all of its CIOs and accounts.¹⁴⁶

PHSA Section 307 (42 U.S.C. §242l): International Cooperation. This section authorizes the HHS Secretary to engage in international cooperation in health research, health statistics, health care technology, health care services, and other activities, especially for HIV/AIDs, tuberculosis, malaria, and other preventable infectious diseases. The section authorizes participation in international meetings, the award of grants, and the exchange of scientists and other fellows with other countries, among other cooperative activities. CDC cites PHSA Section 307 as one authorizing statute for all of its CIOs and accounts.¹⁴⁷

PHSA Section 310 (42 U.S.C. §242o): Health Conferences and Health Education Information. This section requires the HHS Secretary to call annually a conference among state health authorities. The section also authorizes the Secretary to periodically issue information related to public health and requires the Secretary to publish weekly reports on the health conditions in the United States and other countries and other health information. CDC cites PHSA Section 310 as one authorizing statute for all of its CIOs and accounts.¹⁴⁸

PHSA Section 311 (42 U.S.C. §243): Federal-State Cooperation in Communicable Disease Control and Public Health Matters. This section authorizes the HHS Secretary to provide and accept assistance in enforcing quarantine and other health authorities at the federal and state level, and to assist states (and their political subdivisions) in controlling communicable diseases and in other public health matters. The Secretary may provide related assistance and training to states, and may make available resources, such as personnel and medical supplies, to the states that "may be effectively used to control epidemics of any disease or condition and to meet other health emergencies or problems." CDC cites PHSA Section 311 as one authorizing statute for all of its CIOs and accounts, except "Public Health Scientific Services" and "Global Health."¹⁴⁹

PHSA Section 317 (42 U.S.C. §247b): Project Grants for Preventive Health Services. This section allows the HHS Secretary to award grants for preventive health service programs to states, their political subdivisions, and other public health entities. Recipients may receive supplies, including vaccines and other preventive agents, in lieu of grant funds. Subsection (k)(1) specifically authorizes vaccination grant programs. Subsection (k)(2) authorizes grant programs for the prevention and control of diseases and conditions more broadly, including for research, demonstration projects, public information and education programs, and other programs aimed at health professionals. Subsection (l) provides authority to purchase recommended adult vaccines at a negotiated rate, to be provided in lieu of grant funds at the recipient's request. CDC cites PHSA Section 317 as one authorizing statute for all of its CIOs and accounts, except "Global Health" and "Public Health Preparedness and Response."¹⁵⁰

Program-Specific Authorizations

Three CDC centers and institutes and ATSDR are explicitly authorized in law:

• National Institute for Occupational Safety and Health (NIOSH), authorized by the Occupational Safety and Health Act of 1970 (29 U.S.C. §671).
• National Center on Birth Defects and Developmental Disabilities (NCBDD), established in PHSA Section 317C (42 U.S.C. §247b-4).
• National Center for Health Statistics (NCHS), established in PHSA Section 306 (42 U.S.C. §242k).
• ATSDR, established by the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA; 42 U.S.C. §§9601 et seq., at §9604(i)).¹⁵¹

Some of these components were initially established separately from CDC—NIOSH and NCHS, in particular—and were then later transferred to CDC (see the "History and Context" section). Some CDC offices, such as the Office of Women's Health (PHSA Section 310A)¹⁵², are also authorized in law.

CDC also administers program-specific statutes throughout the PHSA and other laws.¹⁵³ Some of these statutes are directed at CDC, for example, the authorization for the Epidemiology and Laboratory Capacity grant program in PHSA Section 2821.¹⁵⁴ Others are directed at the HHS Secretary but carried out by CDC by delegation, for example, an authorization for activities related to the prevention and control of sexually transmitted diseases in PHSA Section 318.¹⁵⁵

The program-specific authorizations that CDC administers vary in terms of specificity, as illustrated in Table 1. Some, such as PHSA Section 318, authorize a general set of public health activities (e.g., research, demonstration projects, and education) with respect to a certain health area (e.g., sexually transmitted diseases). Others authorize and delineate a specific program to be administered by CDC, such as the authorization for the Public Health Emergency Preparedness cooperative agreement in PHSA Section 319C-1, which sets forth eligible awardees, a program funding formula, and other requirements for the grant program.

Many of CDC's specific program authorizations have expired authorizations of appropriations. CDC's FY2025 Congressional Budget Justification lists 29 programs with authorizations of appropriations that have expired in FY2023 or earlier.¹⁵⁶ In general, when Congress appropriates funds for a program whose funding authorization has expired, that appropriation provides sufficient legal basis to continue the program during that period of availability absent indication of congressional intent to terminate the program.¹⁵⁷

Appropriations

In FY2023, CDC/ATSDR had a total program level of $14.5 billion, consisting of $9.3 billion in core public health program funding for CDC and ATSDR and an estimated $5.2 billion for other mandatory spending programs.¹⁵⁸ CDC receives most of its core program funding through the annual Departments of Labor, HHS, and Education, and Related Agencies (LHHS) Appropriations Act. CDC receives LHHS appropriations through accounts that align mostly with the titles of its CIOs. ATSDR is funded by the Departments of the Interior, Environment, and Related Agencies Appropriations Act. CDC also administers several programs that are funded by mandatory spending authorities, such as the Vaccines for Children program and the World Trade Center Health Program (see the "Health Services Programs" section). Congress has also provided CDC with supplemental emergency funding during public health emergencies and other incidents.

Given that many CDC programs are based in general authorities, Congress often uses the appropriations process to inform CDC's programs. Appropriations reports accompanying CDC annual appropriations usually specify programmatic funding levels within CDC accounts, though to varying levels of detail depending on the program and account. For more information on CDC funding, see CRS Report R47207, Centers for Disease Control and Prevention (CDC) Funding Overview.

Activities

CDC uses its general and specific program authorizations, as well as the appropriated funds it receives, to administer programs focused on a wide array of health topics, including infectious diseases, chronic diseases, injury, disability, occupational health, environmental health, and public health emergency preparedness and response. Most of CDC's domestic programs fall within three main categories: (1) support to SLTT health agencies; (2) science and data; and (3) health education and guidance. The discussion below is not exhaustive of all CDC programs but is intended to provide an illustrative view of CDC programs and their scope.

CDC also provides assistance to international governments and organizations through its global health programs, which are not a focus of this report. For more information on CDC global health programs, see CRS In Focus IF11758, U.S. Global Health Funding: FY2020-FY2023 Appropriations.

Support to SLTT Public Health Agencies

Since CDC's inception, one of its primary functions has been to support public health agencies at the SLTT levels. CDC supports these agencies in all areas of public health through technical assistance, guidance, leadership, convenings, funding (primarily through grants, as discussed in the next section), and other material assistance. CDC staff can provide support during outbreaks and other emergencies, including by investigating and responding to threats. For example, through CDC's Epidemiologic Assistance program, SLTT public health agencies can request that EIS officers help investigate public health problems such as "infectious and noninfectious disease outbreaks, unexplained illnesses, or natural or manmade disasters."¹⁵⁹ CDC also administers several fellowship and workforce programs to fund staff at SLTT agencies. CDC staff may also take temporary placement positions within SLTT agencies.

Major Grant and Assistance Programs

CDC administers numerous programs that provide funding or other assistance to SLTT health agencies. In FY2022, CDC obligated a total of $10.3 billion in financial assistance to states and territories. This total includes some direct funding to local governments or organizations within states and some American Rescue Plan Act and other supplemental funding.¹⁶⁰ Of this total, $4.2 billion was spent on direct assistance through the Vaccines for Children program.

Under this Medicaid-financed program, CDC purchases recommended childhood vaccines at a negotiated discounted rate and then distributes them to SLTT public health agencies to provide to eligible children (see the "Vaccines for Children" section).¹⁶¹

CDC also funds many grant programs that finance the public health programs of SLTT government agencies. Some grant programs, such as the Public Health Emergency Preparedness (PHEP) 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. Most CDC grants are awarded to states or territories that are then responsible for distributing funds within their jurisdictions, although some CDC grants are awarded directly to local or tribal agencies. CDC administers many of its grant programs with SLTT agencies as cooperative agreement programs, where CDC staff have substantial involvement with the grantee in program implementation.

Table 2 summarizes the 10 largest CDC grant programs by funding amount in FY2022. These grant awards were funded by both regular and supplemental appropriations (especially American Rescue Plan Act appropriations). In many cases, CDC used appropriations from several different appropriations accounts and budget lines to fund a single program.

Public Health Workforce

CDC offers a variety of internships, fellowships, and training opportunities for students and professionals in public health. Programs include fellowships for public health laboratory professionals, epidemiologists, informaticians, and other public health disciplines. These fellows often serve in SLTT health departments and other public health organizations. Prominent CDC fellowship and workforce programs include the EIS and CDC's Public Health Associate Program.¹⁶²

CDC program grants are also commonly used to pay for SLTT public health staffing and workforce development. The American Rescue Plan Act of 2021 (ARPA)¹⁶³ provided $7.7 billion for public health workforce programs.¹⁶⁴ HHS allocated these funds for many purposes, including to support several new and existing CDC programs.¹⁶⁵ CDC used a large portion of this funding, combined with regular appropriations, to fund a new Public Health Infrastructure Grant program in FY2023. Through this program, CDC awarded $3.7 billion to 107 health departments in all 50 states, Washington, DC, eight territories and freely associated states, and 48 large localities.¹⁶⁶ Recipients are to use this award to hire and retain public health staff, strengthen organization systems and processes, and modernize public health data systems.¹⁶⁷ State health department recipients are expected to distribute a portion of grant funds for public health workforce among local health departments that did not receive direct grant funding from CDC.¹⁶⁸ Given this five-year grant is funded by a one-time appropriation from the ARPA, funds may no longer be available to support hired staff at the end of the five-year period.

Science and Data

CDC supports research and investigation into health challenges, generally with a focus on how they can be prevented and controlled. CDC research explores the distribution and prevalence of health problems and contributing risk factors within populations. CDC research also commonly evaluates the potential interventions to address those risk factors. CDC researchers and scientists come from diverse disciplines, including, for example, epidemiology, veterinary science, microbiology, engineering, economics, social and behavioral sciences, and statistics.¹⁶⁹ Many CDC research articles are published in the agency's Morbidity and Mortality Weekly Report. CDC also awards some research grants and contracts to universities and other research institutions.

In addition, CDC supports laboratory science to aid with detecting and investigating infectious diseases and other health threats. CDC manages federal laboratories that can perform specialized testing to detect new or unusual diseases. CDC also plays a significant role in informing the practices and capacities of the nation's network of public health laboratories. This includes CDC's role in overseeing the Laboratory Response Network (LRN)—a network of laboratories at the federal, state, and local levels that can detect biological, chemical, and other threats, including emerging infectious diseases. (Not all public health laboratories are LRN laboratories.) CDC develops laboratory test kits, protocols, and best practices, and it distributes test kits and supplies to LRN and other public health laboratories. Several grant programs can also support public health laboratory operations and testing.¹⁷⁰

To facilitate public health research and science, CDC has many programs for collecting and analyzing health data. CDC uses the data in its own research and makes data available to outside researchers and sometimes the general public. CDC's data collection programs generally fall into two categories: surveillance systems and surveys.

Surveillance Systems

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 data on an ongoing basis.¹⁷¹ Table 3 provides an illustrative summary of selected CDC surveillance systems. CDC often receives its data from SLTT health departments, mostly on a voluntary basis through data-sharing agreements with those agencies.¹⁷² SLTT health agencies generally collect public health data based on their own legal requirements and policies.¹⁷³ Many CDC grants support SLTT surveillance activities. The data CDC receives, which typically do not include personally identifiable information, help inform an understanding of when, how, where, and to whom disease cases and other health events occur at a population level.

Health Surveys

CDC also administers many surveys, including national population health surveys such as the National Health Interview Survey and surveys of health care providers. CDC's National Center for Health Statistics is one of 13 principal federal statistical agencies (or units).¹⁷⁴

In a population-based health survey, respondents (or a knowledgeable proxy) report information about themselves or about all the people in a household.¹⁷⁵ Population-based surveys can include biological samples for testing, such as blood samples. There is overlap between surveillance systems and surveys. Some surveillance systems involve population-based surveys (e.g., BRFSS). However, not all CDC health surveys are considered surveillance systems.

Health Education and Guidance

CDC conducts education and outreach to many audiences, including the general public, clinicians, and public health practitioners, among others. For example, through its Health Alert Network (HAN), CDC can rapidly share information about urgent public health threats with public information officers, federal and SLTT public health practitioners, and clinicians and public health laboratories.¹⁷⁶ CDC has used the HAN system to issue alerts about diverse health issues, including, but not limited to, rising fentanyl deaths, emerging infectious diseases, recommended health care sanitation procedures, medical product shortages (and associated clinical practice recommendations), and the health effects of natural disasters.¹⁷⁷

CDC also regularly develops educational materials for SLTT agencies, health care providers, and the general public. Health education is a component of almost all of CDC's programs related to specific diseases and health issues.¹⁷⁸ CDC informs the science and practice of public health communication as a part of its mission as well.¹⁷⁹

In addition, CDC develops public health and clinical guidelines based on its expertise in health science and practice. As official recommendations, CDC guidelines are generally not legally binding. Some of CDC's guidelines play a significant role in federal health policy. For example, CDC's Advisory Committee on Immunization Practices (ACIP), made up of nonfederal experts and representatives, makes guidelines and recommendations regarding the use of vaccines and related agents. Based on these recommendations, CDC develops the child and adult immunization schedules of routinely recommended vaccines. ACIP recommendations also inform which vaccines are provided through the Vaccines for Children program (see the "Vaccines for Children" section). ACIP's recommendations also serve as the basis for several statutory health care coverage requirements for vaccines, including for private health insurance, Medicaid, Medicare Part D, and the State Children's Health Insurance Program.¹⁸⁰

CDC also develops and disseminates information on public health and clinical best practices, for example, for youth violence prevention programs or for health care provider conversations about vaccines with patients.¹⁸¹

Regulations

CDC is not primarily a regulatory agency. Administering and enforcing regulations is not a main activity for the agency. As discussed below, however, CDC administers regulations in a few areas:

Medical examination of immigrants and refugees. In 42 C.F.R. Part 34, CDC has developed the medical examination and vaccination requirements for noncitizens seeking to enter the United States as immigrants or refugees. These regulations are based on provisions of the PHSA and the Immigration and Nationality Act.

Interstate and foreign quarantine of people. PHSA Sections 361 through 369 grant the HHS Secretary certain authorities to control the spread of communicable diseases, including through federal quarantine and inspection. Based on these provisions, CDC administers separate regulations for interstate and foreign quarantine in 42 C.F.R. Parts 70 and 71, respectively.¹⁸² These regulations, for instance, specify the conditions under which the CDC Director may authorize the apprehension, medical examination, quarantine, or isolation of an individual with or exposed to certain communicable diseases—known as quarantinable communicable diseases—who is traveling into the United States or between states.¹⁸³ Quarantinable communicable diseases are established by executive order, as explained in the text box above. The regulations also authorize CDC to take action in the event that state or local control of a communicable disease is deemed inadequate to prevent its spread. Such actions may include "measures to prevent such spread of the diseases as [the CDC Director] deems reasonably necessary, including inspection, fumigation, disinfection, sanitation, pest extermination, and destruction of animals or articles believed to be sources of infection."¹⁸⁴

Importation of human remains, certain animals, and infectious biological materials. CDC administers several regulations aimed at preventing and controlling the spread of infectious diseases from imported materials, including from human remains, certain animals, and infectious biological materials.¹⁸⁵ These regulations are all part of 42 C.F.R. Part 71, the foreign quarantine regulations mentioned above.

Federal Select Agent Program. CDC, along with the U.S. Department of Agriculture, administers the Federal Select Agent Program (FSAP), which regulates the possession, use, and transfer of select biological agents and toxins that have potential to pose a public health threat.¹⁸⁶As part of the FSAP, CDC publishes and updates a list of select agents and toxins regulated under the program. Regulated entities are typically laboratories that use these select agents in research. The statutory authorization for the program was established in the Public Health Security and Bioterrorism Preparedness and Response Act of 2002.¹⁸⁷

Occupational Safety and Health Regulations. CDC's NIOSH administers several regulations related to occupational health. For example, 42 C.F.R. Part 37 requires coal mine operators to provide medical examinations to coal miners, as authorized in the Federal Mine Safety and Health Act of 1977.¹⁸⁸ As another example, NIOSH regulates respiratory protective devices, such as N95 respirators, in 42 C.F.R. Part 84.¹⁸⁹

Health Services Programs

CDC administers two large health services programs funded by mandatory budget authorities: the Vaccines for Children program and the World Trade Center Health Program.

Vaccines for Children

The Vaccines for Children (VFC) program is a Medicaid-financed and CDC-administered program to provide recommended childhood vaccines at no cost to eligible children.¹⁹⁰ The Advisory Committee on Immunization Practices determines the list of VFC vaccines through VFC-ACIP Vaccine Resolutions.¹⁹¹

Through VFC, CDC purchases recommended childhood vaccines at a federally negotiated discounted rate. These vaccines are then distributed to SLTT health agencies to further distribute to participating providers.¹⁹² CDC also provides a portion of VFC funding to states for program administration through the Immunization Cooperative Agreement program (in addition to discretionary funding), a grant program that supports state immunization programs.¹⁹³

Children eligible to receive VFC vaccines include those who are (1) Medicaid eligible; (2) not insured; (3) without adequate insurance and who are receiving a vaccine at a federally qualified health center or a rural health clinic; and (4) American Indian or Alaska Native.¹⁹⁴ Participating providers cannot charge patients for the cost of VFC vaccines. Providers may charge patients a fee for vaccine administration as determined by the HHS Secretary, but they cannot deny a vaccine due to inability to pay the fee.¹⁹⁵

Like other Medicaid programs, VFC is an appropriated entitlement program, meaning that funds are provided through annual appropriations but actual program spending is based on need and eligibility. In FY2022, the VFC program spent a total of $5.54 billion.¹⁹⁶

World Trade Center Health Program¹⁹⁷

The World Trade Center Health Program (WTCHP), administered by NIOSH, provides medical monitoring and treatment for certain conditions related to health exposures from the September 11, 2001, terrorist attacks in New York City, at the Pentagon, and in Shanksville, PA. The program currently serves over 110,000 responders and survivors from the attacks. In addition, the program supports some medical research related to 9/11 health exposures.¹⁹⁸

To be covered by the program, individuals must meet eligibility criteria and be certified as having a covered condition related to 9/11 exposure. Current categories of covered conditions include (1) acute traumatic injuries, (2) airway and digestive disorders, (3) cancers, (4) mental health conditions, and (5) musculoskeletal disorders (WTC responders only).¹⁹⁹ Members must receive WTCHP services through several Clinical Centers of Excellence in New York or through a nationwide provider network of certified clinics.²⁰⁰

WTCHP was authorized in 2011 through the James Zadroga 9/11 Health and Compensation Act²⁰¹ (Zadroga Act) which replaced a preexisting similar program funded by discretionary appropriations.²⁰² The Zadroga Act added a new PHSA Title XXXIII, which established a WTCHP Fund that provides annual capped mandatory appropriations for the program. In addition, the City of New York is required to contribute 10% of the annual costs of the program. Since FY2017, annual obligations for program expenses have exceeded the annual appropriated amounts under PHSA XXXIII.²⁰³ CDC has used carryover funding to cover the difference, and Congress provided an additional supplement funds through laws enacted in 2022 and 2023.²⁰⁴ In FY2022, CDC spent $641.5 million on the program.²⁰⁵

Considerations and Options for Reform

Following the COVID-19 pandemic, several stakeholders and Members of Congress have called for CDC reform.²⁰⁶ Some Members in both House and Senate committees of jurisdiction have sought stakeholder feedback on potential CDC reform.²⁰⁷

Defining the Mission

A central question before Congress regarding CDC reform is this: what is the appropriate mission and scope of the agency? Congress most recently defined the scope of the CDC Director's responsibilities in statute as relating to "the investigation, detection, identification, prevention, or control of diseases or conditions to preserve and improve public health domestically and globally and address injuries and occupational and environmental hazards, as appropriate."²⁰⁸

Scoping CDC by Disease and Health Area

There is debate within and outside of Congress on the scope of health topics for CDC. Some have argued that CDC should return to its founding mission and focus on communicable diseases.²⁰⁹ Representative Miller-Meeks stated in a hearing,

The CDC is supposed to be the nation's leading science based communicable diseases agency, not preventable medical diseases or climate change, although those things are very important, with public health being the number one goal, especially as related to communicable diseases.²¹⁰

As recounted in this report, CDC evolved as public health scientists and experts learned to apply the methods developed for communicable disease prevention and control to a wide array of health challenges and threats. Some have argued that CDC's work across diseases and health areas has helped the agency address interrelated health issues.²¹¹ For example, as stated by the Infectious Diseases Society of America and the HIV Medicine Association,²¹²

[W]e recognize the role of noncommunicable diseases in exacerbating the consequences of communicable diseases. We support continued efforts by CDC to address chronic diseases, environmental health and other health threats that negatively impact the ability of individuals to remain healthy during and after exposure to an infectious agent and to recover quickly from illness if they become sick.

Since CDC's founding, the public health field has moved beyond a sole focus on communicable diseases globally. Public health now encompasses efforts to address a wide array of preventable health challenges and to promote health more generally. Yet the broad definitions of public health may raise the question: what health issues and underlying contributors do not fit within CDC's scope?

Scoping CDC by Function

When viewed in terms of functions instead of disease areas or health topics, CDC's scope appears narrower. Across almost all diseases and health areas, CDC's domestic programs generally engage in a core set of activities, as illustrated in the "Activities" section of this report: (1) support to SLTT health agencies, (2) science and data, and (3) health education and guidance.

Some of CDC's programs serve cross-cutting purposes across disease areas. For example, CDC's Health Alert Network is used to alert providers and other health professionals about a wide array of threats and topics: rising fentanyl deaths, emerging infectious diseases, recommended health care sanitation procedures, medical product shortages (and associated clinical practice recommendations), and the health effects of natural disasters.²¹³ As another example, CDC's National Syndromic Surveillance System, which was originally developed for monitoring bioterrorism threats at emergency departments, is now used for monitoring diverse health threats and topics, including COVID-19, influenza, drug overdoses, suicide, health effects of natural disasters, and foodborne illness outbreaks, among others (see Table 3).²¹⁴ CDC's Moving Forward structural review recommended that the agency "support, elevate and empower" cross-cutting functions and core capabilities within the agency.²¹⁵ Thus, CDC itself may seek to further expand programs that crosscut disease or health areas. If Congress is to change or limit the scope of CDC's mission, it may face challenges and questions around how to deal with cross-functional programs, and whether changing the agency's mission would enhance or diminish CDC's work.

Scoping CDC by Role

CDC can also be viewed in terms of the roles it plays. CDC plays a role in preparedness and response to emerging health threats (e.g., epidemics, bioterrorism), but it also supports ongoing disease prevention and health promotion activities. In some cases, these roles are complementary. For example, CDC leveraged its infrastructure for distributing routine vaccines to distribute COVID-19 vaccines during the pandemic on an emergency basis.²¹⁶ As a part of its Moving Forward initiative, CDC is working to become a more response-oriented agency overall, including by expanding emergency response trained staff and functions across the agency.²¹⁷

Other countries have chosen to designate public health prevention and health security functions to separate agencies. For example, during the COVID-19 pandemic in April 2021, the United Kingdom disbanded Public Health England and created a new UK Health Security Agency for health protection capabilities (e.g., pandemic preparedness and response) and transferred existing health improvement, prevention, and other public health functions to other agencies and offices.²¹⁸ Congress could seek further information on the outcomes of the United Kingdom's and other countries' public health agency reforms and structures, and whether any lessons learned could have implications for the United States' federal public health agencies. In the United States, health security functions are currently divided among different HHS agencies.²¹⁹ For example, the Administration for Strategic Preparedness and Response is authorized in statute to coordinate federal public health and medical preparedness for and response to emergencies.²²⁰

Selected Policy Options

Stakeholders and some Members of Congress have proposed policy options for CDC reform discussed in the next sections. These options are not mutually exclusive; Congress could choose to pursue none or all of the options.

Await Results from the Moving Forward Initiative

Some argue that Congress should allow CDC to continue with its own internal reform efforts through the Moving Forward initiative before considering any further legislative reform. Dr. Georges Benjamin, Executive Director of the American Public Health Association, stated at a House hearing with regard to the Moving Forward initiative,

We are supportive of the agency's efforts to address these concerns and believe that Congress should allow the agency the appropriate amount of time to implement these significant changes to its structure and programs. At this time, we do not believe any additional major restructuring is needed to overhaul the agency's structure or programs.²²¹

Some groups argue against further CDC legislative reform. The CEO of the Association of State and Territorial Health Officials (ASTHO) stated, "It is ASTHO's opinion that CDC's mission and purpose are clear to the field and there is no need to authorize the agency further."²²²

If it chooses to maintain the status quo, Congress might consider how to conduct oversight of the agency's ongoing reform efforts. Congress may consider how to evaluate CDC's reforms and determine if and when they have met their intended objectives. Congress might also consider whether to provide CDC with any of the authorities that the agency has requested as a part of the Moving Forward initiative, such as data and workforce authority.²²³

Establish a CDC Reform Process

Several stakeholders have called for Congress to establish a process for considering CDC reform. One independent evaluation, led by the Center for Strategic and International Studies (CSIS), called for "a high-level executive-congressional dialogue on CDC's future." According to the report, the dialogue should involve senior leaders in the White House, HHS, CDC, and Congress to discuss additional reform actions beyond the Moving Forward initiative. The report also proposes establishing an external advisory group to inform long-term reform efforts.²²⁴ Others have recommended similar external review processes by a congressionally established commission to inform CDC reform.²²⁵ Different stakeholders have argued that any review process should include a whole-of-government evaluation of the federal response to COVID-19 inclusive of all agencies and departments, rather than a sole focus on CDC.²²⁶

If it establishes a CDC reform process, Congress faces choices around how to structure such a process. For example, if it establishes an external advisory committee, Congress may consider who should serve on such committee, what areas of expertise should be represented, and how committee members are to be selected. Congress might also wish to direct the committee in how to evaluate CDC to inform its recommendations. Congress might also consider whether to establish a process for formally weighing the committee's recommendations and whether to adopt them in legislation.

Further Authorize CDC

Several stakeholders have called on Congress to formally authorize or codify CDC as an agency.²²⁷ One health policy research center has argued, "Congress should engage in the hard work of outlining exactly what activities the CDC should and should not undertake."²²⁸

CDC is not the only agency within the federal government that lacks an organic or enabling statute established by Congress. Other examples include the Bureau of Safety and Environmental Enforcement in the Department of the Interior and the Health Resources and Services Administration within HHS.²²⁹ According to one analysis by political science scholars, 40% of federal agencies established from 1946 through 1995 were established by executive action rather than legislation.²³⁰

Congress may seek to clarify its policy goals if pursuing CDC formal authorization. Some argue that such authorization would address perceived "mission creep" of the agency and its activities. In particular, some argue that CDC's expanded scope across a wide range of disease areas affected its preparedness and response to communicable disease emergencies such as the COVID-19 pandemic.²³¹ Thus Congress might consider how to appropriately define CDC's mission and scope, as discussed in the "Defining the Mission" section. Congress might also contemplate the powers and capabilities it wishes CDC to have in fulfilling its mission.

In addition, Congress faces choices about the degree of specificity in authorizing CDC and its programs. As summarized in this report, many CDC programs cite general authorities in the PHSA as their statutory basis. This structure has arguably afforded CDC some flexibility to respond to diverse health challenges. For example, in the past few years, CDC has responded to infectious disease outbreaks such as the COVID-19 pandemic and mpox, lung injury associated with electronic vaping devices, rising opioid overdoses and deaths, and the health effects associated with natural disasters.²³² At the same time, formal congressional authorization may provide more explicit direction and perhaps accountability for CDC programs. Congress might consider whether formal authorization will help CDC overcome the issues and challenges faced during the pandemic.

Congress faces many choices in terms of what formal CDC authorization could look like. Congress could choose a flexible authorization, one that would further define CDC's mission and responsibilities but leave specifics of CDC's structure and programs to the agency or HHS. On the other end of the spectrum, Congress could formally authorize and delineate the agency's overall structure and each of its specific programs and activities. As noted in this report, CDC is currently authorized by a mix of general and specific program authorities. Congress could seek to review CDC's existing statutory authorizations, as well as its current programs and activities, to determine the appropriate legislative path forward for the agency.