Identifying Critical Infrastructure During COVID-19

Essential Critical Infrastructure Workers: Communications. Dams. Chemical. Commercial Facilities. Critical Manufacturing. Dams. Defense Industrial Base. Emergency Services. Energy. Financial. Food & Agriculture. Government Facilities. Healthcare & Public Health. Information Technology. Transportations systems. Water. Nuclear Reactors, Materials, & Waste. Department of Homeland Security logo. CISA Cyber + Infrastructure.

NOTE: This information was originally posted on March 19 and was updated on December 16.

Guidance on the Essential Critical Infrastructure Workforce

The Essential Critical Infrastructure Workers Guidance Version 4.0 provides guidance on how jurisdictions and critical infrastructure owners can use the list to assist in prioritizing the ability of essential workers to work safely while supporting ongoing infrastructure operations across the nation.   

CISA issued the guidance originally on March 19, 2020, and published three additional updates to reflect the changing landscape of the nation’s COVID-19 response. While earlier versions were primarily intended to help officials and organizations identify essential work functions in order to allow them access to their workplaces during times of community restrictions, Version 4.0 identifies those essential workers that require specialized risk management strategies to ensure that they can work safely. It can also be used to begin planning and preparing for the allocation of scare resources used to protect essential workers against COVID-19.

If you have feedback or additional questions, please reach out to:

Interim Guidance for Implementing Safety Practices for Critical Infrastructure Workers Who May Have Had Exposure to a Person with Suspected or Confirmed COVID-19

CDC advises that critical infrastructure workers may be permitted to continue work following potential exposure to COVID-19, provided they remain asymptomatic and additional precautions are implemented to protect  them and the community.

16 Critical Infrastructure Sectors

There are 16 critical infrastructure sectors whose assets, systems, and networks, whether physical or virtual, are considered so vital to the United States that their incapacitation or destruction would have a debilitating effect on security, national economic security, national public health or safety, or any combination thereof. Presidential Policy Directive 21 (PPD-21): PPD-21 identifies 16 critical infrastructure sectors.

Chemical Sector

Commercial Facilities Sector

Communications Sector

Critical Manufacturing Sector

Dams Sector

Defense Industrial Base Sector

Emergency Services Sector

Energy Sector

Financial Services Sector

Food and Agriculture Sector

Government Facilities Sector

Healthcare and Public Health Sector

Information Technology Sector

Nuclear Reactors, Materials, and Waste Sector

Transportation Systems Sector

Water and Wastewater Systems Sector

Frequently Asked Questions - General

  1. Why is CISA re-promoting the Essential Critical Infrastructure Worker guidance?

    • This guidance was developed in consultation with government and industry and intended to be updated and refined as we receive additional feedback.
    • It is important that considerations regarding essential critical infrastructure workers continue to inform response policies and activities. The ability of these workers to perform their jobs safely is critical to our Nation’s ability to maintain resilience of National Critical Functions.

    • The current version of this guidance, Version 4.0, is intended to help State, local, tribal, and territorial officials and organizations protect their workers and communities and ensure the continued safe and secure operation of critical infrastructure. The guidance identifies the universe of essential workers that may require specialized risk management strategies to help them work safely.

    • As the Nation enters a new phase of pandemic response, when vaccines are now available in very limited supply, and when infection rates are driving the continued application of public health measures in communities, the guidance may be used by state and local health officials to support COVID-19 vaccine prioritization planning.

  2. What is in 4.0 Version?

    • Version 4.0 provides guidance on how jurisdictions and critical infrastructure owners can use the list to assist in prioritizing the ability of essential workers to work safely to ensure ongoing infrastructure operations and resilience. Doing so will require looking at the universe of workers on the Essential Critical Infrastructure Workforce list and identifying tailored risk mitigation strategies for specific workplace settings. These could include:
      • Identifying those workers that can potentially transition to working from home based on the lessons learned over the past few months from the unprecedented number of teleworkers.  We encourage employers to take a fresh look at the job functions of their workforce to determine if it is necessary for workers to be in the office given the technology breakthroughs that have eased some of the roadblocks to working remotely.
      • Determining the criticality, uniqueness, or specialty of a worker’s role to reduce the need to be at the workplace or working together in close proximity.  There are some functions that are either so essential to supporting the national critical functions and other lifeline support, such as first responders or utility workers, or that are unique or require a special skill set, that these workers must often be at the same workplace or together out in the field.  We recommend that organizations re-examine whether these job functions can be conducted from home and if not, if shift work can be conducted to allow for more social distancing. 
      • Creating a Risk Categorization Methodology for Worker Safety.  We recommend that organizations continue to categorize their employees against a risk factor matrix so that mitigation strategies can be implemented to enhance safety. The risk categorization factors that should be considered include:
      • Setting:  Are workers indoors or outdoors?
        • Proximity: How physically close are workers (and customers) to each other?
        • Type of contact: Do workers touch shared surfaces, common items, and other workers or customers?
        • Duration: How long does an average interaction last?
        • Number of different contacts: How many interactions occur daily?
        • Capability to assess possible infection: Are there screening protocols that protect workers (and customers) from interactions with contagious people?
        • Cleaning: How frequently can the facility be sanitized and cleaned?
      • Determining the allocation of scarce resources for workers, such as personal protective equipment (PPE), other protection, access to testing, and vaccines.  We recommend that jurisdictions and organizations use the essential critical infrastructure worker list as a tool to begin engaging with the essential worker community in the planning for the allocation of potential scarce resources should COVID-19 cases continue to increase. For example, it will be critical that workers who perform essential tasks and/or have consistent interactions with at-risk populations (e.g., the elderly or those with pre-existing conditions) obtain the necessary resources to reduce the transmission of the virus.
    • Based on the responses to these risks, organizations can categorize the conditions that their workers face and continue to implement measures to increase worker well-being.  In other words, increased protective measures should be based on those with high risk factors.
    • An Education section was added to the list of identified essential critical infrastructure workers. Previous versions of the list did not include essential workers in critical infrastructure work settings, such as schools, that were presumed to be closed at the time of publication. Reflecting ongoing national discussions around reopening, this version includes these workers. The Education section is documented as follows:
      • Workers who support the education of pre-school, K-12, college, university, and vocational students, including teachers, teacher aides, special education teachers, ESOL teachers, para-educators, and specialists.
      • Workers who provide services necessary to support educators and students, including but not limited to, administrators, administrative staff, IT specialists, media specialists, librarians, guidance counselors, school psychiatrists and therapists, school nurses, school safety personnel, and providers of before and after school care.
      • Workers that support the transportation and operational needs of schools, including bus drivers, crossing guards, cafeteria workers, cleaning and maintenance workers, bus depot and maintenance workers, and those that deliver food and supplies to school facilities.
      • Workers who support the administration of school systems including, school superintendents and their management and operational staff. 
      • Workers that support child care and protective service programs such as child protective service.
      • Educators and operational staff facilitating and supporting distance learning.
    • Several updates were made to the worker categories, including:
      • Healthcare/Public Health category: “clinical interns” were added to the list;
      • Transportation and Logistics category: “maritime and mariner training and education centers” were added to the list;
      • Public Works and Infrastructure Support Services category: “technicians for elevators, escalators and moving walkways” and “workers who support the operations and maintenance of parks and outdoor recreational facilities” were added to the list;
      • Defense Industrial Base category:  “transportation logistics and cargo handling workers,”  personnel working for the “Department of Transportation” and personnel working in “transportation and logistics” were added to the list;
      • Several categories:  workers “building transportation equipment” were added to several category sections of the list;
    • Other additions include:
      • Updated language regarding businesses and government agencies implementing organization-specific measures that are consistent with applicable Federal, state and local requirements.
      • Language noting that workers should be encouraged to work remotely when possible and organizations are encouraged to identify alternative methods for safely engaging in activities that typically required in-person, non-mandatory interactions.
      • A reference and a link to CDC guidance on when it is safe for infected workers to stop home isolation.
      • A reference and a link to CDC guidance on safety practices for critical infrastructure workers.
      • A reference and a link to CDC guidance to assist businesses and workplaces, plan, prepare, and respond to the pandemic.
      • Updated language on the need for critical essential workers to have consistent access to specific sites, facilities, and assets to ensure continuity of functions.
      • Updated language encouraging open communication between government, emergency managers, and the business community on issues related to worker safety and the continuity of critical functions.
      • Updated language regarding the need for workers to have sustained access and mobility when crossing jurisdictions to perform critical functions, including during times of quarantine.
    • This guidance is intended to support decision makers in communities and jurisdictions across the country during the COVID-19 emergency and it is non-binding.
    • This guidance is not a federal mandate, and final decisions remain with state and local officials, who must make determinations of how to balance public health and safety with the need to maintain critical infrastructure in their communities.
    • For more information on federal response to COVID-19, please visit It remains the most trusted, accurate, and authoritative source of information needed during this pandemic.
  3. Who is this guidance intended for?
    • CISA is issuing this guidance to help government and private sector partners clarify the scope of critical infrastructure and protect the health and safety of key personnel who are essential in operating critical systems and assets as communities continue to reopen. Critical infrastructure requires continuity and resilience to maintain the health and economic wellbeing of communities and the Nation. This continuity will require coordination between government and private sector to ensure key employees are able to work safely. 

  4. How is this different than traditional disasters or emergencies impacting critical infrastructure?

    • COVID-19 is different than any emergency the Nation has faced, especially considering the modern, tightly interconnected economy and American way of life. In traditional emergencies, government coordinates with the private sector to get businesses back to business. In this case, as the government works with partners to slow the spread of COVID-19 and reopen communities, the economic goal is maintaining resilience of the Nation’s foundation—its critical infrastructure. 

  5. What is critical infrastructure?

    • As defined by USA Patriot Act of 2001 (42 U.S.C. 5195c(e)), critical infrastructure includes any “systems and assets, whether physical or virtual, so vital to the United States that the incapacity or destruction of such systems and assets would have a debilitating impact on security, national economic security, national public health or safety, or any combination of those matters.” This definition is appropriately broad to include a wide range of stakeholders who either directly or indirectly enable the functionality of infrastructure systems. 

  6. Who are essential workers?

    • In the modern economy, there are many types of employees required to sustain normal day-to-day services that enable our economy and our way of life. This goes far beyond utilities and public works. This guidance offers an initial baseline for governments and industry to use when identifying key groups of employees that may require accommodation to work safely in order to ensure vital services continue to function during COVID response.
  7. What if this guidance differs from workers identified in Public Health Orders or other requirements issued by State and Local Jurisdictions?

    • The attached guidance was provided to clarify the potential scope of critical infrastructure to help inform decisions by state and local jurisdictions, but does not compel any prescriptive action. Ultimately, those jurisdictions will need to issue guidance that balances the importance of public health concerns with infrastructure resilience imperatives. 

  8. Is this guidance binding?

    • No. This guidance is not binding and is primarily a decision support tool to assist state and local officials. It should not be confused as official executive action by the United States Government.
  9. What are the next steps in this effort?

    • Recognizing that the COVID-19 environment is fluid and unique in our history, CISA will continue to work with the critical infrastructure community to provide supportive tools and analysis to help operationalize this guidance. Future efforts will be responsive to the needs of CISA’s partners across the country in both government and the private sector.
  10. What does it mean to be included on this list?

    • The list of essential workers should be considered by state and local government officials as those with prioritized need to work safely and for access and re-entry into, out of, and through areas where shelter-in-place, quarantine, cordons, and restricted areas. Different jurisdictions may come to different conclusions as to where essential worker accommodation is warranted based on the prevalence and density of certain infrastructure activity and assets in that area.
  11. My job/company is not listed; what now?

    • The intricacies of different jurisdictions and industries means that it is impossible to identify every critical component of every industry across the country. Priorities will also change over time. This guidance is a starting point for jurisdictions to work with their local businesses and for businesses to communicate their needs to their partners in government.
    • There is a well-established critical infrastructure community managed by CISA and partner Sector-Specific Agencies that includes avenues for engagement for government and industry.

Frequently Asked Questions - COVID-19 Vaccine

  • When can Essential Critical Infrastructure Workers get vaccinated?

    • Essential critical infrastructure workers that are health care providers will be vaccinated in Phase IA. Health care personnel are defined as paid and unpaid persons serving in health care settings who have the potential for direct or indirect exposure to patients or infectious materials. Approximately 21 million U.S. health care personnel work in settings such as hospitals, long term care facilities, outpatient clinics, home health care, public health clinical services, emergency medical services, and pharmacies. Health care personnel comprise clinical staff members, including nursing or medical assistants and support staff members (e.g., those who work in food, environmental, and administrative services).
    • There are approximately 90 million essential critical infrastructure workers in the United States, based on CISA’s list of these workers.  Due to this large number of workers, there will not be enough vaccine to vaccinate all essential workers in the early phases of the vaccine distribution when supply is limited. As such, States may further categorize essential workers as either “frontline workers,” those that interact with the public and whose jobs cannot be performed at home, and those that can work from home or have more limited public interface. It is reasonable to assume that “frontline” essential workers may be prioritized to receive the vaccine. These issues are complex and difficult. States will continue to work with the CDC, local health departments, and their constituents to chart the best path forward.
  • How do I determine which phase I will be in to receive the vaccine?

  • How can CISA’s Essential Critical Infrastructure Worker list be used to help SLTT governments determine vaccine prioritization?

    • CISA’s Essential Critical Infrastructure Workers (ECIW) list has been widely used by state, local, tribal and territorial (SLLT) governments to aid their prioritization decisions throughout the pandemic. 
    • More recently, CDC referred to the ECIW as one means to inform the CDC’s recommendation for allocation of COVID-19 vaccine, which offers guidance to federal, state, and local jurisdictions while vaccine supply is limited.  We encourage states and others to refer to CDC’s guidance when making their own plans.
  • How is CISA working with various government agencies on vaccine distribution issues for Essential Critical Infrastructure Workers?

    • CISA has worked with the CDC, the U.S. Department of Health and Human Services, Department of Defense, and other government partners to support the planning for COVID-19 vaccinations throughout the U.S. to ensure that the issues related to the vaccination of essential critical infrastructure workers are understood and prioritized based on the availability of vaccine doses.
    • Specifically, CISA provided the CDC with a technical enumeration of how the Essential Critical Infrastructure Worker was devised, including data sources and occupational group definition codes. The ECIW list was used by the CDC to help build their vaccine prioritization framework.
  • Where can I find out more information about my specific vaccine distribution program?

    • Many state, local, tribal and territorial governments are in the process of finalizing their vaccine distribution plans.  The public should continue to check their State Department of Health/COVID-19 websites for updates regarding vaccine distribution. The CDC has links to State and local websites on the CDC Health Gateway Site.
    • For additional information about COVID-19 vaccination plans, please visit CDC's Coronavirus Frequently Asked Questions page on their website.

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