CDC has updated its guidance for people who are fully vaccinated. See Recommendations for Fully Vaccinated People.
CDC recommends schools continue to use the current COVID-19 prevention strategies for the 2020-2021 school year. Learn more
Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more

Public Health Guidance for Potential COVID-19 Exposure Associated with Travel

Public Health Guidance for Potential COVID-19 Exposure Associated with Travel
Updated Apr. 27, 2021

To reduce introduction and spread of new variants of SARS-CoV-2, CDC issued an Order effective January 26, 2021. It requires all air passengers arriving to the US from a foreign country to get tested for COVID-19 infection no more than 3 days before their flight departs and to provide proof of the negative result or documentation of having recovered from COVID-19 to the airline before boarding the flight. For more information on this testing requirement, see the Frequently Asked Questions.

CDC has separate guidance for exposures in healthcare personnel and critical infrastructure workers, and for quarantine of contacts of persons with COVID-19.

Cruise ships in U.S. waters or intending to return to U.S. waters must continue to follow CDC’s Framework for Conditional Sailing Order (CSO) and the Technical Instructions for Mitigation of COVID-19 Among Cruise Ship Crew.

Summary of Recent Changes

As of April 27, 2021

  • Added vaccines with emergency approval from the World Health Organization to the definition of “fully vaccinated”

View Previous Updates


The COVID-19 pandemic has spread throughout the world. Individuals who travel may be at risk for exposure to SARS-CoV-2, the virus that causes COVID-19, before, during, or after travel. This could result in travelers’ spreading the virus to others at their destinations or upon returning home.

As part of a broader strategy aimed to limit continued new introduction of SARS-CoV-2 and the emergence of new SARS-CoV-2 variants into U.S. communities, all travelers should remain vigilant for signs and symptoms of COVID-19, and take recommended precautions to limit community spread after traveling from one location to another. CDC has issued requirements and recommendations to prevent travel-associated exposure to and transmission of SARS-CoV-2.

As vaccination efforts continue across the United States, the proportion of travelers who are fully vaccinated will continue to increase. Travel-associated transmission risk is likely to be substantially reduced among those fully vaccinated with an effective vaccine, although global circulation of SARS-CoV-2 variants of concern and vaccine performance against emerging variants, and global vaccination coverage remain a concern. As such, CDC has updated its guidance for fully vaccinated travelers to account for these considerations. The guidance is also updated to align with existing guidance for people who have recovered from COVID-19 in the previous 3 months.

People are considered fully vaccinated 2 weeks after they have received the second dose in a 2-dose series (Pfizer-BioNTech or Moderna), or 2 weeks after they have received a single-dose vaccine (Johnson and Johnson (J&J)/Janssen).1

Audience and Purpose

This page provides U.S. public health officials with an overview of CDC’s requirements, recommendations, and considerations for management of domestic and international travelers with potential SARS-CoV-2 exposure.

Requirements, Recommendations, and Considerations

CDC’s requirements, recommendations, and considerations for public health management of international and domestic travelers are provided below. Health departments have the authority to exceed CDC recommendations in their jurisdictions. Travelers should additionally follow guidance and requirements of destination countries for international travel, or state, tribal, local, and territorial authorities when arriving in a U.S. jurisdiction after international or domestic travel.

Mask Requirement

As of February 2, 2021, CDC requires wearing masks during travel on public transportation conveyances (e.g., airplanes, ships, trains, buses, taxis, ride-shares) arriving into, moving within, or departing the United States (including U.S territories) and in U.S. transportation hubs (e.g., airports, ports, bus and train stations). See more information about this requirement.

Predeparture Testing Requirements and Recommendations

Predeparture testing may detect travelers infected with SARS-CoV-2 before they initiate their travel.  Testing does not eliminate all risk, but when predeparture testing is combined with self-monitoring for symptoms of COVID-19, wearing masks, social distancing, and hand hygiene, it can make travel safer by reducing spread on conveyances and in transportation hubs.

Predeparture Testing Requirement for International Air Passengers Traveling to the United States

CDC requires all air passengers two years of age or older coming to the United States, including U.S. citizens, to present a negative COVID-19 test result from a nucleic acid amplification test (NAAT) or antigen test (“viral test”) conducted no more than 3 days before their flight’s departure. Passengers who have had a positive viral test in the past 3 months (or the time period specified in CDC guidance) and have met the criteria to discontinue isolation may travel with documentation of recovery from COVID-19. This documentation of recovery must include their positive viral test result and a letter from a licensed healthcare provider or a public health official that states the individual is cleared for travel. More information about this requirement is available in the Frequently Asked Questions. These requirements remain in place for fully vaccinated travelers.

U.S. Predeparture Testing Recommendations for Outbound International Travelers and Domestic Travelers

Travelers who are fully vaccinated or who recovered from COVID-19 in the past 3 months do not need to get tested before departing the United States for international travel or before domestic travel unless their destination requires it. CDC recommends predeparture testing with a viral test no more than 3 days before departure for other travelers departing from the United States for international destinations or traveling domestically within the United States.

CDC modeling indicates that predeparture testing is most effective when combined with self-monitoring (Johansson et al.). Travel should be delayed (i.e., individuals should self-isolate) if symptoms develop or a pre-departure test result is positive. Testing before departure results in the greatest reduction of transmission risk during travel when the specimen is collected close to the time of departure. Testing more than 3 days before travel provides little benefit beyond what self-monitoring alone can provide. Furthermore, a lower sensitivity test (e.g., antigen test) closer to the time of travel (i.e., with rapid availability of results) can be as effective as, or more effective than, a higher sensitivity NAAT (e.g., reverse transcription polymerase chain reaction test [RT-PCR]) performed several days before travel. Predeparture testing should be completed and results provided to the traveler before travel is initiated. Travelers who test positive should remain in isolation and delay travel until they meet criteria for discontinuing isolation. Travelers whose test results are not available before departure should delay their travel until results are available.

CDC modeling indicates that testing on the day of travel provides the greatest reduction in transmission risk while traveling (Johansson et al). However, for logistical reasons (e.g., rebooking of travel and avoiding potential exposures in airport terminals where social distancing may be challenging), CDC recommends departing air travelers get tested before they initiate travel, rather than at the airport immediately prior to their flight. Testing is being offered at a number of airports, both domestically and internationally, and many air travelers are choosing to get tested in airports because of convenience and ease of access. If testing is offered in airport settings, all results (positive or negative) must be reported in real time to the health department of jurisdiction, and positive results in departing air travelers should be reported immediately to both the local health department and the CDC quarantine station of jurisdiction. Ideally, travelers’ consent should also be obtained before testing to notify the airline of a positive result. Plans should also be in place to prevent travel of persons who test positive and their travel companions, who in most cases would be considered close contacts, including request by the health department to CDC for use of federal public health travel restrictions and denial of boarding by the airline (see section below). Testing sites should also have plans to manage individuals who test positive and their travel companions, including temporary isolation or quarantine and safe private transportation home that does not involve public transportation.

U.S. Post-arrival Testing and Management Recommendations

Travel poses a risk of introducing additional cases of COVID-19 to destination communities. All travelers (international or domestic) should be advised to take precautions to protect others until 14 days after arrival, including social distancing, wearing masks, hand hygiene, and monitoring themselves for symptoms of COVID-19. The following are CDC’s recommendation for travelers arriving in a U.S. jurisdiction based on traveler status.

Fully vaccinated travelers

Domestic travel (within the United States or to a U.S. territory):

  • Fully vaccinated travelers do not need to get a SARS-CoV-2 viral test after domestic travel, unless they are symptomatic or testing is required by local, state, or territorial health authorities.
  • Fully vaccinated travelers do not need to self-quarantine following domestic travel.

International travel:

  • Fully vaccinated international travelers arriving in the United States are still recommended to get a SARS-CoV-2 viral test 3-5 days after travel.
  • Fully vaccinated travelers do not need to self-quarantine in the United States following international travel.

Travelers who are not fully vaccinated and have not recovered from COVID-19 in the past 3 months (international and domestic)

  • These travelers are still recommended to have a post-arrival test 3-5 days after arrival at destination, combined with self-monitoring and a 7-day period of staying home (or in a comparable location such as a hotel room) or otherwise self-quarantining
    • The 7-day period should be completed even if the test is negative.
  • In the absence of testing, this period should be extended to 10 days.
  • Travelers should avoid contact with people at higher risk for severe illness for 14 days, regardless of testing.

Travelers who recovered from COVID-19 in the past 3 months

Below we provide technical considerations for U.S. health departments in developing their strategies for post-arrival management of travelers, including the timing of testing and using testing in combination with other measures.

Note: These considerations are specifically intended for management of asymptomatic travelers with no known exposures to a person with COVID-19. They are not intended to be used in developing policies for management of individuals with probable or confirmed COVID-19 or those who have had close contact to a person with COVID-19.

Technical Considerations on Testing and Post-arrival Management for Travelers who are not Fully Vaccinated (based on CDC modeling)

Mathematical models have provided some insights to potential effects of testing and various quarantine periods. CDC modeling suggests that, when combined with post-arrival testing and self-monitoring for symptoms of COVID-19 (with subsequent isolation for those who test positive or develop symptoms), the period of staying home (self-quarantine) or in a comparable location such as a hotel (referred to as stay-at-home period in the remainder of this section) can be shortened without substantially increasing the risk of introducing additional cases of COVID-19 to the destination community (Johansson et al).

The optimal post-arrival test timing and reduction in risk of introducing additional cases of COVID-19 at destination (referred to as transmission risk in the remainder of this section) vary depending on what other measures are taken. The scenarios below assume all travelers self-monitor for symptoms of COVID-19 and self-isolate if symptoms develop.

Stay-at-home (Self-quarantine) Period with or without Post-arrival Testing

  • With a stay-at-home period for 14 days after travel (i.e., with or without testing), the transmission risk can be almost eliminated. Although a 14-day stay-at-home period provides the greatest reduction in transmission risk, it may be perceived as burdensome and incompatible with critical work or essential errands, and compliance may be poor.
  • Combined with a 7-day stay-at-home period, testing at 3-4 days post-arrival is optimal and provides a comparable reduction in transmission risk to a 14-day stay-at-home period. To achieve this level of risk reduction, the 7-day period should be completed even if the test is negative. For practical purposes, the post-arrival testing period may be extended to 3-5 days after arrival at destination.
  • A stay-at-home period of 10 days without testing provides a greater reduction in risk than post-arrival testing alone, regardless of when the testing occurs.

Predeparture Testing and Post-arrival Testing with No Stay-at-home Period

  • The combination of predeparture and post-arrival testing provides additional risk reduction over either predeparture or post-arrival testing alone, with a moderate reduction in transmission risk at destination.

Post-arrival Testing Alone with No Stay-at-home (Self-quarantine) Period

  • A single test at 1-3 days post-arrival provides a greater reduction in transmission risk at destination than a single test before travel, although the reduction in risk is still relatively small.

Predeparture Testing with No Post-arrival Management (other than symptom monitoring)

  • Predeparture testing is important to prevent transmission during travel but is less likely to detect infections in travelers who might have been exposed after their predeparture test or who were infected close to the time of testing.
  • Such travelers are likely to experience their entire infectious period in the destination location and, therefore, pose the highest transmission risk at destination.

See Science Brief: Background Rationale and Evidence for Public Health Recommendations for Fully Vaccinated People for modeling and rationale used to inform CDC’s updated guidance for fully vaccinated travelers.


Johansson MA, Wolford H, Paul P, et al. Reducing travel-related SARS-CoV-2 transmission with layered mitigation measures: Symptom monitoring, quarantine, and testing. Available at: https://www.medrxiv.org/content/10.1101/2020.11.23.20237412v1external icon

Clifford S, Quilty BJ, Russell TW, Liu Y, Chan Y-WD, Pearson CAB, et al. Strategies to reduce the risk of SARS-CoV-2 re-introduction from international travellers. medRxiv. 2020; 2020.07.24.20161281. doi:10.1101/2020.07.24.20161281

Ashcroft P, Lehtinen S, Angst DC, Low N, Bonhoeffer S. Quantifying the impact of quarantine duration on COVID-19 transmission. medRxiv. 2020; 2020.09.24.20201061. doi:10.1101/2020.09.24.20201061

Quilty BJ, Clifford S, Group2 C nCoV working, Flasche S, Eggo RM. Effectiveness of airport screening at detecting travellers infected with novel coronavirus (2019-nCoV). Eurosurveillance. 2020;25: 2000080. doi:10.2807/1560-7917.ES.2020.25.5.2000080

Wells CR, Townsend JP, Pandey A, Krieger G, Singer B, McDonald RH, et al. Optimal COVID-19 quarantine and testing strategies. medRxiv. 2020; 2020.10.27.20211631. doi:10.1101/2020.10.27.20211631

Individuals with Confirmed or Probable COVID-19 or Known Exposure to Someone with COVID-19

Individuals with confirmed or probable COVID-19 should remain in isolation and delay travel until they meet criteria for discontinuing isolation. Individuals who have been exposed (i.e., close contacts) to a person with confirmed COVID-19 should remain in quarantine and delay travel until they meet criteria for release from quarantine. Health departments may request use of federal public health travel restrictions for individuals with confirmed COVID-19 or with known exposure, if they intend to travel before being cleared to do so by public health authorities, by contacting the CDC quarantine station with jurisdiction for the area where the person is located.

If travel is necessary (e.g., to obtain medical care that is not available locally), transportation should be conducted in a manner that does not expose conveyance operators (e.g., air crews, bus drivers) or other travelers. The mode of transportation should be guided by distance (e.g., ground vs. air transportation) to final destination as well as the clinical condition of the traveler (i.e., whether medical care may be needed en route).

  • Options for travelers with confirmed or probable COVID-19 are private vehicle, chartered or private aircraft, or medical transport (i.e., ground or air ambulance) with infection control precautions in place to protect vehicle operators and medical personnel).
  • Options for travelers with known exposure to someone with COVID-19 are private vehicle or chartered or private aircraft with precautions in place to protect air crews.

For international transport with a destination within the United States, per CDC regulations (42 Code of Federal Regulations, Part 71: Foreign Quarantineexternal icon), the conveyance operator must notify CDC in advance through the CDC quarantine station with jurisdiction for the port of entry or the CDC Emergency Operations Center (770-488-7100 or eocreport@cdc.gov). The aircraft operator should also coordinate with the U.S. embassy or consulateexternal icon for the country where the individual is located, CDC, the Federal Aviation Administration, and U.S. Customs and Border Protection, as well as appropriate foreign, state, local, territorial, and tribal governments to ensure compliance with all applicable laws and regulations. For more information see Interim Guidance for Transporting or Arranging Transportation by Air into, from, or within the United States of People with COVID-19 or COVID-19 Exposure.

International Air Passenger Contact Information

CDC supports domestic COVID-19 control efforts by making contact information for international air passengers available to state and local health departments for the purpose of public health follow-up or contact tracing. At present, collection of traveler contact information is occurring for passengers from countries subject to entry restrictions under Presidential Proclamation.

Follow-up with travelers may include contacting travelers, providing instructions for what travelers should do if they develop illness compatible with COVID-19, follow-up of test results, and intermittent check-ins during the post-arrival period. Mobile applications or automated text messaging may be useful to provide information to travelers or conduct monitoring of travelers. Follow-up with travelers is at the discretion of health departments and may be considered by jurisdictions that are implementing containment measures. Decisions about whether to conduct follow-up and what it would involve could be based on the status of the COVID-19 outbreak in the jurisdiction, status of the COVID-19 outbreak in travelers’ countries or states of origin, the volume of travelers, available resources, competing priorities of public health officials, and other factors, as applicable.

Crews on Passenger or Cargo Flights

CDC and the Federal Aviation Administration have jointly provided Updated Interim Occupational Health and Safety Guidance for Air Carriers and Crewspdf iconexternal icon. This FAA-CDC guidance includes recommendations for aircrews to self-monitor under the supervision of their employer’s occupational health program and to remain in their hotel rooms to the extent possible and practice social distancing while on overnight layovers. As long as crew members re­­­­­main asymptomatic, have no known exposures to a person with COVID-19, and have not tested positive for SARS-CoV-2, they may continue to work on flights into, within, or departing from the United States. CDC’s testing requirement for international air passengers includes a limited exemption for air crews. Crew members who follow their carrier’s occupational health plan as well as the FAA-CDC guidance are also not subject to CDC’s recommendation to stay at home (self-quarantine) after international air travel. If they develop fever, cough, shortness of breath, or other symptoms of COVID-19, or test positive for SARS-CoV-2, crew members should self-isolate and be excluded from work on commercial flights until cleared to work by their employer’s occupational health program following CDC’s criteria for Discontinuation of Isolation for Persons with COVID-19 Not in Healthcare Settings.

Crew members who have known exposure (i.e., close contacts) to a person with COVID-19 should be excluded from work and remain in quarantine until they meet criteria for release from quarantine. While air travel is a vital economic activity, CDC does not recommend allowing crew members with known exposures to continue to work prior to meeting these criteria, even if asymptomatic, because of the inability of crew members to remove themselves from the workplace if they develop symptoms during a flight and the challenges involved in effectively isolating a symptomatic person on board an aircraft.

Previous Updates

1 This guidance applies to COVID-19 vaccines currently authorized for emergency use by the U.S. Food and Drug Administration: Pfizer-BioNTech, Moderna, and Johnson and Johnson (J&J)/Janssen COVID-19 vaccines. This guidance can also be applied to COVID-19 vaccines that have been authorized for emergency use by the World Health Organization (e.g. AstraZeneca/Oxford).