State, tribal, local, and territorial (STLT) public health agency staff serve on the frontlines, protecting the health and safety of the American people. These professionals are tasked with delivering Foundational Public Health Services (FPHS), which reflect the minimum program areas and capabilities that STLT public health agencies, regardless of their size or resources, should provide for the communities they serve.¹ The FPHS framework identifies the following 5 foundational areas: communicable disease control; chronic disease and injury prevention; environmental public health; maternal, child, and family health; and access to and linkage with clinical care. These foundational areas cover the basic public health programs and expertise needed to serve communities. Additionally, the framework outlines 8 foundational capabilities needed within an agency’s infrastructure, which range from assessment and surveillance to community partnership development. STLT public health agencies use the framework to build and strengthen local delivery of FPHS to address both immediate and long-term population health outcomes.

Although the FPHS form the core of public health functions, often STLT public health agencies must deliver services with insufficient capacity.² A major contributor to insufficient capacity is workforce gaps.³ Recent estimates indicate the public health field needs approximately 80 000 additional full-time staff, representing an increase of 80% from 2019 staffing levels, to deliver the core FPHS.² This shortage is complex and involves challenges with recruiting, hiring, and retaining qualified staff and securing sufficient and sustainable funding.^3,4

Public health workforce training programs are one strategy to support STLT public health agency workforce gaps and provide FPHS in their jurisdictions.^3,4 The U.S. Centers for Disease Control and Prevention’s (CDC) Division of Workforce Development (DWD) offers a portfolio of competency-based and experiential-service fellowship and training programs designed to bolster national public health workforce capacity.⁵ Public health agencies, STLT or otherwise, may apply annually to serve as host sites for DWD’s fellows, such as those in the Epidemic Intelligence Service (EIS) and Laboratory Leadership Service (LLS), among other fellowships. For 2 years, EIS and LLS trainees are embedded within their host public health agency, where they complete discipline-specific training while working on priority projects and activities selected by their host sites. CDC funds trainee salaries, benefits, and fellowship-associated costs like travel or software licenses, and host sites provide a workspace and experienced public health professionals to serve as supervisors. The placements are mutually beneficial arrangements supplementing public health agencies’ workforce while trainees gain invaluable knowledge and experience in applied public health. By providing structured opportunities to gain practical experience, these fellowships can serve as a crucial mechanism for augmenting the STLT public health workforce and strengthening their workforce capacity to deliver FPHS.

We used existing EIS and LLS fellowship data sources to show how trainees support STLT public health agencies. To illustrate trainee contributions to host site workforce capacity, we described where recent trainees had been assigned and the nature of their day-to-day assignments. To demonstrate value to their host sites, we shared perspectives from host site supervisors of recently graduated trainees. To highlight how trainees can serve STLTs when temporary surges in workforce are needed, we showed trainee participation in STLT public health agency-led rapid response activities. Together, our findings describe how public health workforce training programs can alleviate workforce strains and enhance foundational services provided by STLT public health agencies to their communities.

From February to April 2024, we conducted a rapid evaluation of EIS and LLS trainee support to STLT public health agencies. We focused on describing direct support provided by trainees placed within STLT public health agencies. We also described indirect support through requests from STLT public health agencies for specialized rapid response assistance. The analysis was retrospective and leveraged existing fellowship data. Descriptive analyses were used to summarize quantitative data via Excel spreadsheet exports from each source.

Our rapid evaluation showed that EIS and LLS fellows play a vital role in strengthening STLT public health agencies in foundational and emergency response services. Most recent trainees are in states, and some territories and freely associated states, although fewer trainees are assigned to host sites primarily serving tribal communities. Public health workforce shortages are substantial in rural and underserved areas.^2–4 STLT public health agencies serving these communities face challenges such as limited resources, higher disease burden, and greater difficulty recruiting and retaining qualified public health professionals.³ Despite the wide geographic coverage, how trainee placements differ by population density or by community characteristics is unclear. Future assessments might explore trainee placements using a range of characteristics to illuminate specific areas where increased support might be directed. STLT public health agencies in these communities with no EIS or LLS trainees should consider how these fellowships can provide strategic support while navigating their workforce gaps. Increased support for STLT public health agencies through public health fellowships might help mitigate the challenges they experience in public health service delivery.

Regardless of geographic setting, EIS and LLS trainees support host sites across all FPHS areas, although with some distinctions between fellowships. As expected, EIS distributions showed these trainees support a broader range of public health program areas, compared with LLS trainees. Although laboratory functions play a crucial role in certain areas, they are not required across all public health program areas. In contrast, epidemiology functions are more broadly applicable and distributed across a wider range of program areas. Our findings also showed that EIS and LLS contribute substantially to enhancing assessment and surveillance capabilities in their host sites. These contributions support the intent of these 2 fellowship programs as EIS primarily provides trainees with training in applied epidemiology, including disease investigation epidemiologic research and surveillance; whereas LLS ensures its trainees are competent in public health laboratory operations, quality, and safety. A high demand exists for certain public health specialties, including epidemiologists and laboratorians.^7,8 Furthermore, the recent COVID-19 pandemic illustrated the need for strong communicable disease control programs in addition to ensuring robust public health programming in other FPHS areas, such as chronic disease and environmental health.⁹ Given their diverse academic and professional backgrounds and the specialized didactic and experiential fellowship training, EIS and LLS trainees are well positioned to serve as qualified candidates who can fill crucial workforce capacities in STLT public health agencies.

Beyond the day-to-day work, EIS and LLS trainees also play a crucial role in supporting STLT public health agencies in rapid response to public health emergencies, whether as part of their host site assignment or through short-term rapid response assistance. Future assessments of trainee contributions should investigate the barriers and facilitators that exist for STLT public health agencies requesting and engaging CDC for rapid response support. In recent years, numerous public health threats have emerged, including highly infectious disease outbreaks like recurrent Ebola, mpox, and measles and environmental emergencies such as hurricanes and wildfires. As demonstrated during the COVID-19 pandemic, staffing shortages are worsened during public health emergencies, and gaps in critical technical expertise hamper the ability of STLT public health agencies to effectively respond and provide adequate service delivery.^2,3,10–12 Having trained professionals who can rapidly deploy during emergencies is necessary for accurate testing, surveillance, and response to different public health threats, including infectious diseases, chemical spills, and bioterrorism. STLT public health agencies should continue using the CDC’s specialized rapid response assistance mechanisms as a flexible strategy to meet urgent workforce staffing needs during public health emergencies. EIS and LLS trainees have proven essential to bolster activities, such as field interviewing, contact tracing, specimen testing, data analysis, and developing effective communication messages. In addition to meeting staffing criteria, these fellowship placements and response assistance mechanisms to place fellows in STLT and provide response efforts come at minimal or no cost to jurisdictions, mitigating the challenge of financial compensation associated with surging the workforce during emergencies.¹⁰ These fellowships not only help fill gaps in routine service provision but also serve as an agile and trained pool of public health professionals capable of responding quickly to emerging health threats in communities across the nation.

This analysis has certain limitations. First, the fellowship data on trainee placements represent only 2 cohorts. Although this gives an idea of where and what type of work recent EIS and LLS trainees have supported in their host sites, a longer timeframe can provide a richer understanding of trainee contributions to STLT public health agency functions. Additionally, the nature of trainee work activities described is general and high-level and does not dive into the specifics of individual trainee projects or work activities. Future assessments might focus on specific trainee activities to provide more detailed insights into the day-to-day work conducted or supported through these fellowships. Additionally, future evaluations can include the Public Health Associates Program, which also embeds trainees in STLT public health agencies and might replicate this analysis to further illuminate CDC fellowship contributions to the public health workforce.^13,14

Public health fellowship programs play a vital role in strengthening and supporting STLT agencies by providing skilled trainees and graduates ready to enter the workforce full-time after fellowship completion. CDC embeds a considerable number of trainees in STLT public health agencies, meeting both foundational public health areas and specialized rapid response needs. This host site model allows trainees to benefit by gaining hands-on experience and developing a deep understanding of STLT agency operations. After their fellowship training, these graduates are equipped with skills to support the agencies they are placed in, whether at the federal, state, tribal, local, or territorial levels. Federal training programs can serve to cultivate a robust public health workforce within STLT public health agencies.