Nearly one million people enter the United States each day, according to U.S. Customs and Border Protection (CBP). While the vast majority experience smooth entry, some travelers are denied admission, detained, or sent back — a reality that has drawn renewed attention after recent reports of phone searches and deportations at U.S. airports.
Here’s a clear breakdown of what travelers need to understand before heading to the U.S.
What Documents Are Required to Enter the U.S.?
Entry requirements depend entirely on your immigration status.
For U.S. Citizens
All U.S. citizens must present a valid U.S. passport when flying into or out of the country — including infants and children. CBP also accepts:
- NEXUS cards for U.S. citizens departing from designated Canadian airports
- Enhanced driver’s licenses
- Trusted Traveler cards such as Global Entry, SENTRI, or NEXUS
- Enhanced tribal identification
Those arriving by land or sea must show approved Western Hemisphere Travel Initiative (WHTI) documents. While alternate IDs may be accepted in some cases, carrying a passport is always recommended.
Additionally, U.S. passport applicants are now required to list sex assigned at birth, not self-identified gender.
For Green Card Holders
Lawful permanent residents must present a valid green card or a reentry permit to return to the U.S.
- Green cards are valid for one year of international travel
- Reentry permits are valid for two years
Those who exceed these limits may need to apply for a Returning Resident (SB-1) visa.
For Foreign Nationals and Visa Holders
Requirements vary depending on visa type, travel purpose, and country of citizenship.
Who Needs a Visa to Enter the U.S.?
- U.S. citizens and permanent residents do not need visas to reenter
- Citizens of Canada and Bermuda generally do not need visas
- Travelers from 40+ approved countries may enter under the Visa Waiver Program (VWP) for up to 90 days with ESTA approval
However, travelers who have visited:
- Cuba since January 12, 2021
- Or North Korea, Iran, Iraq, Libya, Somalia, Sudan, Syria, or Yemen since March 1, 2011
may be ineligible for visa-free entry and must apply for a visa instead.
Can a U.S. Citizen Be Refused Entry?
According to the American Civil Liberties Union (ACLU):
- U.S. citizens cannot be denied entry into the country
- However, they can be detained or questioned if they refuse to answer CBP officers at the border
Permanent residents are generally protected as well, though secondary screening is still possible.
What Can Make a Non-Citizen Inadmissible?
Immigration law lists multiple legal grounds for refusal of entry. According to immigration law expert Fernando Chang-Muy of the University of Pennsylvania Carey Law School, these include:
- Serious health conditions (such as tuberculosis)
- Criminal history
- National security concerns or terrorism links
- Risk of becoming a public financial burden
- Intent to work illegally
- Missing or fraudulent travel documents
- Prior immigration violations
If border officials determine that any of these apply, entry can be denied immediately.
What Happens If You’re Denied Entry?
Non-citizens usually face three possible outcomes:
- Immediate Return: You may be placed on the next flight home at the airline’s expense
- Secondary Screening: Additional questioning and medical or security checks
- Detention: For serious cases involving fraud, security concerns, or false documents
What Are Your Options If Entry Is Denied?
- Permanent residents must be given a reason for denial and can seek legal assistance
- Asylum seekers may still request protection, but fast-track removals now make approvals harder
- Visa denials typically cannot be appealed due to U.S. consular discretion
- Travelers may:
- Reapply for a visa later
- Request an ineligibility waiver
There is no guaranteed legal review for visa applicants applying from outside the U.S.
Key Takeaway
While most travelers enter the United States without issue, entry is never guaranteed unless you are a U.S. citizen. Proper documentation, clean travel history, and full honesty at the border remain essential for smooth admission.
