Travel to the United States is not limited to tourism, business, study, employment, or permanent immigration. Several other visa categories and entry processes exist for more specific purposes. These include transit through the US, seeking private medical treatment, undertaking official government duties, performing temporary religious work, working as a crewmember, or entering under humanitarian arrangements. This guide outlines these categories and the requirements that apply.
Section A: Transit Visas
Foreign nationals travelling through the United States on their way to another destination may require a transit visa. Even brief layovers must be covered by the correct authorisation to ensure lawful entry and onward travel. Nationals of Visa Waiver Program (VWP) countries must obtain Electronic System for Travel Authorization (ESTA) approval for transit, even if they do not leave the airport. ESTA is travel authorisation only; admission is determined by US Customs and Border Protection (CBP).
1. Transit Visa (C)
A C visa is issued when the sole purpose of entering the United States is to transit en route to another country. The visa cannot be used for sightseeing, tourism, or other activities outside the scope of immediate onward travel. Extensions or changes of status are not permitted.
2. Visitor Visa (B)
Where the traveller intends to leave the airport or spend time in the United States during a layover, a B visa may be required. The B category allows limited short-term activities such as visiting friends or attending brief meetings, subject to the standard visitor rules.
3. Visa Waiver Program (VWP)
Nationals of designated VWP countries may transit through the United States without a visa if they secure ESTA approval and meet all programme requirements. The stay is limited to a maximum of 90 days and covers transit as well as other permitted visitor purposes. CBP officers will make the final decision on entry at the port.
Section Summary: Transit through the United States may be covered by a C transit visa, a B visitor visa where short visits are planned, or ESTA under the VWP for eligible nationals. The correct option depends on nationality, whether the traveller leaves the airport, and compliance with VWP limits.
Section B: Medical Treatment
Foreign nationals can enter the United States for private medical care. Applicants must provide evidence of treatment arrangements with a US healthcare provider, proof of financial means to pay for treatment and living costs, and assurance that they will return home after treatment. Documentation should also show why treatment in the United States is required instead of in the applicant’s home country.
1. Visitor Visa (B)
The B-2 visitor visa is the standard route for medical treatment. Applicants must submit medical reports and letters from a US hospital or physician detailing the diagnosis and planned treatment. They must also demonstrate the ability to fund the treatment, accommodation, and related expenses. A USCIS petition is not required, but the application must be well-documented to avoid refusal.
2. Visa Waiver Program (VWP)
VWP nationals may receive medical care under ESTA approval if their stay does not exceed 90 days and they meet programme conditions. Supporting documents may be requested by CBP at the border. Using ESTA for medical treatment carries risk, as entry can be refused if officials are not satisfied with the evidence presented.
Section Summary: Medical treatment in the United States is usually based on a B-2 visa supported by comprehensive evidence. VWP travellers may use ESTA if eligible, but their stay is capped at 90 days and CBP retains discretion at the border.
Section C: Official Government and Diplomatic Travel
The United States grants specific visa types for foreign government officials, accredited diplomats, international organisation staff, and military personnel on official duty. These visas reflect the official nature of the travel and may extend to immediate family members.
1. Diplomatic and Foreign Official Visas (A)
A visas are issued to diplomats and government officials travelling on official assignments. Immediate family members may qualify for derivative A visas where they accompany or follow-to-join the principal applicant. These visas are tied to the official’s assignment and must not be used for private travel.
2. International Organization Employees (G) and NATO Visas
G visas cover staff of recognised international organisations such as the United Nations. NATO visas are issued to representatives and staff of the North Atlantic Treaty Organization. Spouses and children of eligible applicants may also qualify. Applicants must be entering to perform official functions with their organisation.
3. Foreign Military Personnel
Foreign military posted in the United States generally require A-2 or NATO visas. These can be renewed if the assignment is extended. Eligible dependants may also receive derivative status. Visitor visas cannot be used for official military travel.
Section Summary: Diplomatic and official travel categories include A visas for accredited officials, G visas for international organisation staff, and NATO visas for alliance representatives. Military staff use A-2 or NATO visas. Dependants may qualify where conditions are met.
Section D: Religious, Crewmember, and Humanitarian Visas
Other specific visa categories cover temporary religious work, crew duties, and limited humanitarian situations. Each category has its own eligibility requirements and procedures.
1. Religious Worker Visa (R)
The R visa permits ministers and religious workers to work in the United States for a qualifying religious organisation. The organisation must be a bona fide non-profit, tax-exempt body recognised under US law. A USCIS petition from the US employer is required, and applicants must demonstrate a history of affiliation with the religious organisation. R status is typically granted for 30 months and may be extended to a maximum of 5 years.
2. Crewmember Visa (C-1/D)
Crewmembers working on ships or aircraft that travel to the United States require a C-1/D visa. This visa is linked to crew duties and does not permit extended shore leave or employment outside the crew role. Crew duties cannot be carried out under a standard visitor visa.
3. Humanitarian and Special Processes
Humanitarian entry is provided under refugee resettlement, asylum, or parole programmes, rather than standard visa categories. Refugee and asylee family members may benefit from derivative processes known as “follow-to-join.” These are administered by USCIS and the Department of State under specific statutory frameworks.
Section Summary: R visas are used for religious workers, C-1/D visas for active crew members, while humanitarian pathways operate through refugee, asylum, and parole procedures, not traditional visa applications.
FAQs
1. Do all medical visitors need a visa?
Most applicants require a B-2 visa. Nationals of VWP countries may travel with ESTA approval, but their stay is limited to 90 days and CBP may refuse entry if medical evidence or proof of funds is insufficient.
2. Can a transit visa be used for short sightseeing?
No. A C visa is strictly for transit. Travellers who wish to leave the airport or undertake sightseeing must apply for a B visa or, if eligible, use the VWP with ESTA approval.
3. What is the difference between A and G visas?
A visas are issued to accredited diplomats and government officials. G visas apply to employees of recognised international organisations. Both visa types may extend to eligible family members.
Conclusion
The United States provides a range of visas and entry processes beyond the more common tourism, business, study, and employment routes. These include transit, medical treatment, diplomatic and official travel, religious work, crew duties, and humanitarian entry. Each option carries specific eligibility rules, evidentiary requirements, and limits. Selecting the correct pathway and complying with its conditions is critical to ensuring lawful entry and avoiding disruption to travel.
Glossary
| Transit Visa (C) | Permits passage through the US en route to another country; cannot be used for sightseeing or extended stays |
| Visitor Visa (B) | Covers tourism, medical care, and limited transits; requires strong evidence for medical cases |
| Visa Waiver Program (VWP) | Allows eligible nationals to enter without a visa for up to 90 days, with ESTA approval |
| A Visas | For diplomats and accredited government officials; may cover immediate family |
| G Visas | For employees of recognised international organisations and their dependants |
| NATO Visas | For NATO representatives and staff travelling on official duty; covers dependants |
| Religious Worker Visa (R) | Temporary status for ministers and religious workers employed by a US non-profit; max stay 5 years |
| C-1/D Visa | For crew members of ships and aircraft entering in connection with their duties |
| Humanitarian Programs | Special processes such as refugee resettlement, asylum, and parole; not standard visa categories |
Useful Links
| US Visas – Official State Department |
| Other Visa Categories – State Department |
| ESTA Application – Visa Waiver Program |
| USCIS Humanitarian Programs |
