What Is A Public Health Agency?

By Dr. Jessica Sapp  |  09/08/2026

Public health agencies are government organizations responsible for protecting and improving the health of the populations they serve. Their work focuses largely on preventing disease and injury, promoting healthy behaviors, monitoring community health, and responding to health threats and emergencies.

Public health agencies operate at the local, state, national, and international levels. Their responsibilities can affect everything from disease control and environmental health to emergency preparedness and access to essential public health services.

Understanding the role of public health agencies also helps people to better recognize how public health decisions, programs, and resources affect the health and safety of their own communities. For people seeking a job opportunity in public health, understanding how these agencies function also offers a closer look at how communities identify health needs, respond to challenges, and work to improve population health.

Public Health Agencies in The United States

The first U.S. public health agency, the Marine Hospital Service, was formed in 1798. According to the Centers for Disease Control and Prevention® (CDC), “In 1902, the agency’s name changed to Public Health and Marine Hospital Service, and finally in 1912, to reflect its growing responsibilities, the agency was renamed the United States Public Health Service (USPHS).”

Today, public health agencies operate across three primary levels in the United States:

• Local
• State
• Federal

While their responsibilities sometimes overlap, each level plays a distinct role in preventing disease, addressing health problems, and protecting the health of communities.

Local Public Health Agencies

Across the country, more than 3,300 local health agencies support public health programs in their communities. Local public health agencies typically include city, county, district, or regional health departments that address the health needs of their communities.

Depending on their jurisdiction, these agencies may provide services that address disease prevention, environmental health hazards, and other community health needs, such as:

• Immunizations
• Health education
• Environmental health programs
• Communicable disease control

Local health departments also monitor community health status to identify health concerns, guide prevention efforts, and determine which local public health services are most needed. The specific services available can vary based on community needs, funding, state law, and the agency’s size and structure.

Although local health agencies derive their authority from state laws, their governance structures vary. In some communities, local boards of health help establish policies and priorities or provide oversight of public health activities.

State Public Health Agencies

New York established the nation’s first state-level public health agency in 1866. Today, state health agencies or health departments oversee public health programs in all 50 states and U.S. territories. In 60% of states, state health departments are governed by boards.

State public health and human services departments take a broader view of the health needs affecting people across a state. Their responsibilities often include:

• Tracking diseases and health trends
• Coordinating emergency response efforts
• Managing statewide public health programs
• Providing resources and guidance to local health departments

However, public health is not organized exactly the same way in every state. Some states have more centralized systems, while others give local health departments greater independence.

In either case, state and local agencies often work together to share data, coordinate programs, and respond to health problems that may affect multiple communities. For example, Florida’s county health departments (e.g., Brevard, Orange, and Miami-Dade) operate as part of the statewide public health system overseen by the Florida Department of Health.

Federal Public Health Agencies

Federal public health agencies address health issues that affect people across the country. Many of these agencies operate within the U.S. Department of Health and Human Services (HHS). Their work ranges from monitoring disease outbreaks and conducting medical research to regulating food and medications and preparing for public health emergencies.

Some of the most recognizable federal public health agencies include:

• Administration for Children and Families (ACF)
• Administration for Community Living (ACL)
• Agency for Healthcare Research and Quality (AHRQ)
• Advanced Research Projects Agency for Health® (ARPA-H®)
• Administration for Strategic Preparedness and Response (ASPR)
• Agency for Toxic Substances and Disease Registry (ATSDR)
• Centers for Disease Control and Prevention
• Centers for Medicare & Medicaid Services (CMS)
• Food and Drug Administration (FDA)
• Health Resources and Services Administration (HRSA)
• Indian Health Service (IHS)
• National Institutes of Health (NIH®)
• Substance Abuse and Mental Health Services Administration (SAMHSA)

What Does A Public Health Agency Do?

The work of a public health agency can show up in everyday life in more ways than people may realize. From monitoring disease outbreaks and supporting vaccination programs to inspecting food safety and preparing communities for emergencies, public health agencies focus largely on preventing health problems before they become more widespread.

Although there are many public health specialties, some agencies focus on a particular area of specialty. These areas may include community health, environmental health, policy development, or health care services.

Public health agencies work to improve population health through a wide range of programs and services. Their responsibilities can include:

• Managing vaccination programs to control infectious diseases
• Enforcing regulations to protect food safety and maintain clean air
• Developing community programs and campaigns that encourage healthy behaviors and lifestyles
• Promoting health equity by identifying healthcare access disparities
• Monitoring health trends and disease outbreaks
• Performing epidemiology and surveillance to track disease
• Collaborating with researchers and community organizations for wellness
• Protecting and improving community health
• Creating programs for healthy lifestyles in communities

In the United States, many of these responsibilities are reflected in the 10 Essential Public Health Services, a framework for protecting and promoting health in communities. These essential services include assessing population health, investigating health concerns, and communicating health information. Other services include strengthening community partnerships, improving access to care, and supporting a competent public health workforce.

Working for A Public Health Services Agency

Public health agencies rely on professionals with a wide range of skills and backgrounds to provide essential public health services. In 2022, local health departments across the United States employed approximately 182,000 public health workers.

Depending on the position and employer, career opportunities may be available in areas such as epidemiology, health education, environmental health, emergency preparedness, health policy, data analysis, and community health. By 2024, health departments employed 5,706 epidemiologists, a 38% increase from 2021. Funding can also shape the resources and staffing available to public health agencies.

Education requirements vary by role. Some positions may require a bachelor’s degree in public health or a related field, while more specialized or leadership roles may require graduate-level education, professional certifications, or relevant work experience. Together, these professionals help build a competent public health workforce equipped to respond to changing health needs and serve diverse communities.

For people interested in this field, earning a public health degree can provide a foundation in areas such as disease prevention, health promotion, research, policy, and population health.

The Bachelor of Science in Public Health at APU

For adult learners who want to study public health, American Public University part of American Public University System (“APU”) offers an online Bachelor of Science in Public Health. Students can take courses in a variety of subjects, such as epidemiology, public policy, and public health in America. Other courses include health services organization and health economics and finance.

This degree has four concentrations to enable students to choose courses best suited to their professional goals: General, Emergency and Disaster Management, Nutrition and Wellness, and Public Health Informatics.

For more information, visit APU’s nursing and health sciences program page.

Centers for Disease Control and Prevention®, CDC®, Advanced Research Projects Agency for Health®, ARPA-H®, and NIH® are registered trademarks of U.S. Department of Health and Human Services.