Even as more of the population becomes vaccinated, Americans traveling abroad have an extra hurdle to jump through on their way home. Because of an executive order issued by President Biden last year, all travelers entering the United States must show their airline a negative test result taken within three days of departure or show proof they’ve recovered from covid-19 in the past 90 days. There are no exceptions for those who have been vaccinated.

The State Department and the Centers for Disease Control and Prevention continue to advise Americans against taking discretionary trips abroad, regardless of vaccination status. While the CDC has said inoculated people can travel with less risk, much of the world is still not vaccinated, and experts are wary of new coronavirus variants that continue to spread or mutate.

David Beuther, a pulmonologist at National Jewish Health, a leading respiratory hospital, echoed those concerns. Not only will the situation vary from place to place, he said, but it’s also in constant flux.

“If a person is going to travel, then they get to all these questions about how do I get tested? Do I need to isolate? What kind of test? I have to make sure I get my results in a timely manner. Can I rely on the test? Will they accept it?” Beuther said. “It gets really, really complicated.”

Nonetheless, some Americans are continuing to travel outside the United States and will have to navigate restrictions accordingly. Here is what they should consider before their trip.

What kind of test do travelers need?

Per the executive order, those traveling by air who are at least 2 years old must get a polymerase chain reaction (PCR) or rapid antigen test within three days of their flight. Travelers will have to provide the airline a paper or electronic copy of their results before boarding.

Travelers who have recovered from covid-19 will have to provide the airline proof of their recovery, including a recent positive test and a letter from a doctor or public health official.

The PCR lab test is considered the gold standard of coronavirus testing but can cost more and takes a few days to process results. Antigen tests are faster and cheaper but tend to be less accurate.

Rapid tests “miss sometimes up to a quarter of cases where somebody is sick and the test is falsely negative,” Beuther said.

Will testing requirements make travel safer?

Experts warned after the order was issued that it couldn’t guarantee infected patients wouldn’t make it onto planes. Even countries with strict testing requirements — including New Zealand and Australia — have reported cases of infectious travelers testing negative before flights.

“No test is perfect, and no strategy is perfect,” Beuther said. “But they are thought to be better than nothing, and hopefully we catch a few people who don’t think they’re sick and prevent them from coming into the country and globally.”

Where can travelers find a test abroad?

The State Department says travelers can find information on where to get a test overseas by visiting the U.S. Embassy website of the country they’re visiting. But Americans won’t be able to get tested at the embassies.

An additional resource is the site TestForTravel.com, which features crowdsourced information on finding coronavirus tests abroad.

As a convenience for guests, many hotels are offering to arrange coronavirus tests that comply with the new order. That may be on-site at a hotel medical facility or in a guest room, or at nearby health clinics or hospitals.

Tour companies are also providing such pandemic amenities. For example, adventure travel operator Aggressor Adventures has return-travel testing services that arrange a rapid antigen test with a medical lab tech at the end of trips to near or far-flung destinations including the Maldives, Costa Rica and the Bahamas.

Depending on their departure city, travelers might find a coronavirus test at the airport, but check ahead of time to see whether there’s a testing center on site, what hours it operates and whether customers need an appointment.

The CDC also says that self-tests may be used to return to the U.S. as long as they follow specific criteria.

The self-test must be an FDA-approved SARS-CoV-2 viral test (nucleic acid amplification test or antigen test) that includes real-time supervision from a telehealth service, among other conditions. One option is Abbott’s BinaxNOW kit, which promises results in 15 minutes.

Can I get tested at my hotel?

A number of resorts in the Caribbean and elsewhere are currently offering testing to guests. Tests will vary in cost depending on the type administered and the location.

At some all-inclusive Club Med resorts — including properties in Mexico and on the Turks and Caicos Islands — guests can obtain free antigen testing. Couples Resorts’ four properties in Jamaica offer free on-site rapid tests and will provide results via email within 24 hours. And at Papagayo Beach Hotel in Curaçao, guests can get an on-site antigen test for $20 or a PCR test for $90.

What happens if a traveler tests positive?

According to the State Department, those who test positive will not be able to fly to the United States as planned. The CDC order requires airlines to deny boarding to any passenger who doesn’t provide proper documentation of their test results or recovery.

Travelers who test positive must stay where they are until they’ve recovered, which could take anywhere from days to several weeks.

“Those choosing to travel or remain abroad should be prepared to make their own arrangements regarding their medical care, and to remain informed regarding all travel requirements,” a State Department said in an email.

The State Department urges all those traveling internationally to have a backup plan in case they test positive. They should consider where they’d be able to stay, if they’d be able to afford a significantly longer trip and how their life at home may be impacted should they need to stay abroad for weeks. Some travelers may want to get a travel insurance policy to cover the costs of becoming sick with the coronavirus abroad.

Do travelers need to quarantine when they get to the U.S.?

On Jan. 26, the Biden administration implemented an executive order that requires anyone flying into the United States to follow the CDC guidance to self-quarantine for at least seven days.

However, the CDC told The Washington Post in an email that it will not enforce its guidelines for quarantine as a rule, and has also said vaccinated people do not need to self-quarantine after travel.

While not mandatory, quarantining remains strongly recommended, as a negative test result alone doesn’t guarantee a traveler is coronavirus-free.

Read more: