Visa and Immigration Information

For International Patients/Caregivers

The NIH Clinical Center conducts clinical research on a broad spectrum of diseases and health problems. On occasion, NIH accepts international patients as clinical research participants. Those patients arriving from abroad will need to obtain a B-2 temporary visitor’s visa for medical treatment prior to entering the United States for medical treatment.

The following immigration information is separated into six parts to explain the steps required to enter and remain in the U.S. for the purpose of medical treatment.

Part 1: Consular information needed before you arrive at NIH

All international patients receiving treatment at NIH as well as their caregivers need a B-2 visa issued by the U.S. Consulate or Embassy in their country of origin.

The B-2 visa allows international patients and caregivers to enter the U.S. and obtain an extension to stay, if needed, to receive treatment at NIH.

In determining eligibility for a B-2 visa, the consular officer at a U.S. embassy or consulate will assess the following factors:

  • if the patient maintains a residence outside of the United States which they do not intend to abandon,
  • if the patient intends to enter the U.S. for a limited time,
  • if the patient seeks admission to engage in legitimate activities: no unlawful or criminal activities.

It is the responsibility of the patient and/or caregiver to overcome the presumption of immigration intent and provide evidence that they will return to their country of origin once treatment/evaluation ends.

NIH research teams assist with the visa application process by sending the patient an invitation letter. If the patient needs a caregiver, the letter includes the caregiver's name and the reason why he/she must accompany the patient. This letter will communicate the NIH's intent to treat the patient's specific condition, and to the extent possible, detail the projected length of treatment.

The consular officer may also ask the patient for a medical diagnosis and confirmation from a local, consular-approved physician. The diagnosis will explain the nature of the illness and the reason the patient requires treatment in the U.S.

In addition to the NIH invitation letter, the visa applicant must provide the consular officer with documents showing ties to the country of origin. For example, the applicant can demonstrate permanent employment, meaningful business and financial connections, close family ties, or social and cultural associations. The applicant must also provide documentation that they have sufficient funds to cover expenses for their visit and departure from the U.S. International patients should investigate and plan for potential care options following completion of the research protocol at NIH. Any rehabilitation or long-term care in the U.S. needs to be arranged through an insurance provider and/or completely out-of-pocket.

A visa is a stamp, issued by the U.S. Department of State, placed in the applicant's passport. It is issued by a U.S. embassy or consulate. A visa can be issued for one or multiple (M) entries and can have an expiration date and validity between one day and 10 years. The expiration date on the visa is the last day the applicant can enter the U.S. Once this date has passed, the applicant cannot use this visa to enter the U.S. and must apply for a new visa.

Once granted, the B-2 Visa does not guarantee the applicant's right to enter or remain in the United States, or to acquire a new visa in the future. A visa simply allows the applicant to apply for admission at a U.S. port of entry, but the ultimate decision on whether or not, and under which statutes, the applicant will be admitted rests with the U.S. Customs and Border Protection of the Department of Homeland Security.

Sample US visa stamp

A sample of a U.S Visa MRV document (not valid for travel)
*The final section at the bottom of the stamp is a machine read only reference section.

The Visa Waiver Program (VWP)

The VWP waives the entry visa requirement for individual who are citizens of certain countries. Entry under the VWP has a strict, non-renewable 90-day limit period of stay in the U.S. Once the 90-day period has expired, patients who use the VWP must leave the U.S. NIH will be unable to help patients or their caregivers extend their stay if they come under the VWP. All international patients and their caregivers who come from VWP countries should get a B-2 visa when visiting the U.S. for treatment at NIH. Because medical care events are not always predictable, a B-2 visa is imperative for patients and caregivers even when they do not expect to stay longer than 90 days. With a B-2 visa, the patient or caregiver can extend their stay in the U.S. without needing to leave the country.

For more information about the VWP and those passport holders who may be eligible to use the program, please visit the U.S. Customs and Borders Protection's website:

<< Back to Top >>

Part 2: Arrival to the United States

Upon arrival, you will be inspected by a U.S. Customs and Border Protection (CBP) officer. The CBP officer will review your documents and admit you to the U.S. in B-2 status for a specific period of time. The CBP officer will stamp your passport with an arrival stamp and enter your biographical and visa information into an electronic record system. The electronic record, known as a Form I-94 "Arrival/Departure Record," can be accessed online at after your arrival to the U.S. The “admit until” date on your Form I-94 indicates the date your status in the U.S. expires. You must depart the U.S. prior to your "admit until" date unless your medical care requires that you remain in the U.S. If you need to continue your medical treatment in the U.S., an extension request must be filed with the U.S. Citizenship and Immigration Services before the Form I-94 “admit until” date.

<< Back to Top >>

Part 3: Maintaining B-2 status while in the U.S.

It is important to remember that as a B-2 Visitor for medical treatment, you are limited to activities that involve your medical treatment and general tourist type activities. Engaging in inappropriate activities will lead to violations of your immigration status and make you subject to denial of extensions, deportation and denied future re-entry.

To avoid problems with immigration issues while in the U.S., please:

  • Maintain a valid passport at all times. If your passport will expire while you are in the U.S., you may apply and obtain a new passport from your home country's embassy in the U.S.
  • Engage only in activities permitted by your B-2 status. U.S. Federal laws prohibit any individuals under B-2 status to:
    • DO NOT
      • Enroll in primary, secondary or university studies. Enrolling in classes while in B-2 status will result in a status violation. Individuals in B-2 status, who have violated their nonimmigrant status by enrolling in classes, are not eligible to extend their B-2 status or change to another status. These regulations provide no exceptions. In addition, enrolling a child in classes may cause them and their family members to be refused a visa to enter the U.S. in the future.
      • Engage in employment while in the U.S. Employment is performing any actions that generate income.
  • Apply for an extensions of stay before your "admit until" date is reached.

<< Back to Top >>

Part 4: Information about extending your stay to complete treatment

Patients and caregivers who need to continue their stay may be eligible for assistance in preparing requests for extensions of stay. If you have questions regarding this, please contact or call the Social Work department at 301-496-2381 and ask to speak to someone regarding nonimmigrant services.

Please contact the Social Work department four months prior to the expiration date on your Form I-94. If you continue to need medical treatment at the NIH, the Social Work department will make an appointment with a staff member to help you extend your stay.

Patients and caregivers must depart the U.S. upon completion of their treatment. If you remain in the U.S. after the end date of your Form I-94 without submitting an extension request, it may cause problems with future visits to the U.S.

<< Back to Top >>

Part 5: Important Reminders

NIH does not assist patients with issues unrelated to their medical stay at NIH.

Examples include:

  • Obtaining a "green card"
  • Paperwork related to a marriage, work permits, or refugee or asylum requests
  • Extensions of stay for individuals who entered the country under the Visa Waiver Program.

Humanitarian parole, also known as "humanitarian visa"

When the U.S. Department of State denies an applicant a B-2 visa, some applicants may be eligible to enter the U.S. by applying for humanitarian parole. This type of visa is issued by the Department of Homeland Security. A U.S. resident or U.S. citizen must sponsor the applicant. Information on obtaining humanitarian parole can be found at:

Humanitarian parole is not recommended for patients who need to remain or receive treatment at NIH for an extended period of time. Once the time limit granted on the humanitarian parole expires, it is very difficult, and sometimes impossible, to obtain extensions of time. In that case, the applicant will need to return to his country of origin.

<< Back to Top >>

Part 6: Immigration Information

The Clinical Center works with the NIH Division of International Services (DIS) to provide applicable immigration services and updates. DIS has a staff of highly talented immigration specialists available to assist the international patient population. DIS must receive a referral from the NIH Social Work department in order to provide immigration services to a patient at the Clinical Center.

Rules and regulations may change without notice. It is important that patients and caregivers refer to the Department of Homeland Security website for the most up to date policies and news:

International patient questions can be directed to the Clinical Center at
Disclaimer: This information is provided for your assistance. No warranty is provided as to its accuracy or usefulness. It is not meant to replace the information from Federal agencies responsible for immigration services.

This information is prepared specifically for persons taking part in clinical research at the National Institutes of Health Clinical Center and may not apply to patients elsewhere. If you have questions about the information presented here, talk to a member of your health care team.

Products/resources named serve as examples and do not imply endorsement by NIH. The fact that a certain product/resource is not named does not imply that such product/resource is unsatisfactory.

<< Back to Top >>

NOTE: PDF documents require the free Adobe Reader.

This page last updated on 07/28/2023

You are now leaving the NIH Clinical Center website.

This external link is provided for your convenience to offer additional information. The NIH Clinical Center is not responsible for the availability, content or accuracy of this external site.

The NIH Clinical Center does not endorse, authorize or guarantee the sponsors, information, products or services described or offered at this external site. You will be subject to the destination site’s privacy policy if you follow this link.

More information about the NIH Clinical Center Privacy and Disclaimer policy is available at