Foreign national scientists' spouses and unmarried children under 21 are considered dependents for immigration purposes. Dependent family members may enter the U.S. in a derivative status such as J-2 Exchange Visitor (dependent of J-1) or H-4 Dependent (dependent of H-1B). The dependent's primary purpose for entering the U.S. is to accompany the primary foreign national scientist while they conduct research at NIH.

Family members who are not considered dependents (parents, siblings, children over 21, and unmarried domestic partners) typically apply for a nonimmigrant business/tourist visitor visa, the B-1/B-2 visa, to visit the United States. Family members from certain countries may be eligible to visit for up to 90 days without first obtaining a visa through the U.S. Department of State Visa Waiver Program.

Each Embassy or Consulate has specific instructions for the B-1/B-2 visa application process. Select the appropriate Embassy/Consulate on the Department of State website and follow the online instructions for the "visitor" visa. Department of State guidance on visa eligibility and documentation requirements is also available.

DIS does not provide any documentation for non-dependent family members. However, scientists may request a fellowship verification letter from their Institute or Center.

NIH scientists may also provide non-dependent family members with the following:

• Invitation letter or e-mail that specifies their relationship to the visitor, the dates and purpose of the visit, where visitor will stay in the U.S., and any other pertinent information
• Copy of NIH scientist’s immigration documents (e.g. Form DS-2019)
• If necessary, evidence that the NIH scientist can support the visitor while in the U.S.
• For example, if scientist is providing for room and board of the visitor, include this information in the invitation letter/e-mail

Short-term visitors who come to the U.S. in B-1/B-2 status or in WT/WB status via the Visa Waiver Program have no grace period and must depart the U.S. by the end date indicated on their most recent Form I-94.​