Travel Restrictions to Limit the Spread of Contagious Diseases
To help keep everyone safe, federal public health authorities have tools in place to limit the spread of serious contagious diseases during travel. These measures may apply to people traveling into, out of, or within the United States – especially if someone is known or suspected to be infectious.
The goal of these travel restrictions is simple: reduce the risk of illness spreading on planes and other forms of transportation. By doing so, they help protect travelers, airline and transportation workers, and the communities people are traveling to and from.
Why Travel Restrictions Exist
Public health officials play an important role in helping prevent the spread of serious illnesses, especially when travel is involved. Diseases like tuberculosis, measles, and other highly contagious infections can spread quickly if someone travels while sick.
That’s why these precautions exist – to help protect fellow travelers, airline crews, and the broader public, and to reduce the risk of exposure along the way.
Main Tools Used to Restrict Travel
The Centers for Disease Control and Prevention (CDC), working alongside federal partners, relies on two primary tools to manage travel-related health risks.
Do Not Board List
The CDC places individuals who are known or suspected to have a contagious disease on the Do Not Board List. This action prevents them from receiving a boarding pass for commercial flights to, from, or within the United States. The Transportation Security Administration (TSA) enforces these restrictions at airports.
Public Health Lookout
A Public Health Lookout alerts U.S. Customs and Border Protection (CBP) when a traveler who may pose a health risk attempts to enter the United States by air, land, or sea. CBP then notifies public health officials, who assess the situation and determine whether medical evaluation, isolation, or other actions are necessary.
Together, these tools help prevent potentially infectious individuals from traveling while also allowing public health authorities to intervene at ports of entry when needed.
Who Can Be Subject to Travel Restrictions?
Travel restrictions are applied only under specific circumstances. Generally, they may be used when:
- A person is known or suspected to be infectious with a serious contagious disease.
- The traveler doesn’t realize they’re sick or may choose not to follow public health guidance.
- The person plans to travel internationally or use commercial transportation.
- Public health officials need to step in to help protect other travelers and the public.
Historically, these measures have been used for conditions such as infectious tuberculosis and, more recently, for diseases including COVID-19 and mpox.
How Travel Restrictions Are Lifted
Once public health officials determine that a person is no longer at risk of spreading illness, travel restrictions are usually removed. CDC regularly reviews cases—often every two weeks—to confirm whether continued restrictions are necessary.
Key Points to Know
- Travel restrictions are public health tools, not criminal penalties.
- Being subject to a Public Health Lookout does not automatically prevent entry into the United States.
- These measures are intended to protect travelers, transportation staff, and destination communities.
CDC’s Role in Port Health
CDC operates a network of Port Health Stations at major U.S. points of entry. These stations help reduce the introduction and spread of communicable diseases by supporting public health actions during travel. This includes:
- Screening travelers arriving by air, land, or sea for signs of illness.
- Working with federal, state, and local partners such as CBP and TSA.
- Providing guidance to airlines and maritime operators on managing illness during travel.
Legal Authority Behind Travel Health Measures
Federal law gives the CDC the authority to act when travel could put public health at risk. Under legislation like the Public Health Service Act, the CDC can work through established regulations to examine individuals, manage potential health risks, and, when necessary, limit travel to help prevent the spread of communicable diseases.
Please Note: This information is up to date as of publication but is subject to change without notice. For the latest information, visit the official CDC website.
