Adult consumption of marijuana for medical or recreational purposes is legal in many states, including Washington State. Consumption also effectively is decriminalized (but still illegal) in British Columbia, Amsterdam, and other cities and provinces. Yet foreign citizens who have ever smoked pot or consumed any type of cannabis — even where it is legal — can be caught in a trap when they come to the U.S. border.

When a foreign traveler flies, drives or sails into the United States, an Immigration Officer with Customs & Border Protection (CBP) under the Department of Homeland Security may inquire about marijuana use. They may ask questions, or, if the traveler permits access to cell phones or other technology devices, they may draw inferences from information on the technology, including from photographs or Facebook or other social media posts. Vacation photos, including visits to Seattle that feature the traveler posing in front of retail marijuana shops, can result in several hours in a CBP detention room, followed by denial of entry into the United States.

Under U.S. immigration law, if the foreign traveler admits to use of marijuana that is in any way unlawful, the person will be refused entry. This rule applies even if the consumption was outside the United States (in a country where such use is illegal) or inside a state within the United States where consumption was legal under state law. And don’t expect the CBP officer to cut you any slack; he or she simply has no discretion to ignore admitting to the facts of an illegal act, even if made under duress. The person will be found inadmissible and removed from the U.S. as soon as possible. The bar is “permanent,” unless the person is granted a waiver of inadmissibility.

There are three factors weighed in a waiver decision:

(1) The risk of harm to society if the applicant is admitted into the U.S.;

(2) The seriousness of the prior violation; and

(3) The reasons for wishing to enter the country.

Canadians can make a waiver application at a U.S.-Canada port of entry. Citizens from other countries apply through a U.S. consulate or embassy outside the United States. The waiver process can take the better part of the year, but, if successful, should result in a waiver. Even then, the waiver is only good for five years though it can be renewed (which is a recent improvement over the prior one-year waiver period).

When a CBP Immigration Officer asks questions, your answers must be truthful (and no, there is no exception for “but I didn’t inhale”). However, a foreign traveler can decline to answer a question — and also can refuse to relinquish a cell phone or to grant social media access. Foreign travelers declining to answer are best served by being polite and as composed as possible. The Immigration Officer’s response may be, “I guess you’re not coming in today.” However, a temporary delay is almost always a more favorable result than a permanent bar, and allows time to contact an immigration lawyer to assess options or to apply for a waiver before your next visit to the United States.