Spouses and children under the age of 21 of H-1B employees are considered dependents and are eligible for H-4 nonimmigrant status. H-4 beneficiaries are only eligible to be in the U.S. in H-4 status while the principal H-1B beneficiary is in the U.S. in valid H-1B status.
Most H-4 dependents are not authorized to work in the U.S., and are not eligible for a social security number.
There is a limited exception to this rule for certain H-4 dependent spouses of H-1B visa holders who are in the employment-based permanent residence process. To be eligible, the H-1B principal must either be the beneficiary of an approved I-140 immigrant visa petition, or have been granted a post-sixth-year extension of H-1B status under Section 106 of the American Competitiveness in the Twenty-First Century Act of 2000.
If traveling outside and re-entering the U.S, H-4 dependents need to ensure that they have a valid passport, a valid H-4 visa stamp, visas, and if applicable, the Form I-797H Approval Notice for a change of status to, or extension of, H-4 status.
Dependents may seek to change their nonimmigrant status to H-4, or extend their current H-4 status. An application to change or extend status requires the filing of an application on Form I-539/I-539A, with filing and biometrics fees, to USCIS. Applicants will be required to attend a biometrics appointment at a local, designated office as part of the application process.
While OVIS can provide general guidance on the I-539 process, the application is a personal application and is the responsibility of the dependent applicant. OVIS can provide referrals to outside immigration counsel if the dependent applicant seeks legal advice and assistance with the application.
Changes or extensions of status may take weeks or months to be processed by USCIS, and international travel is prohibited when the application is filed, and while it is pending. For this reason, you may wish to consider traveling overseas to apply for the H-4 visa stamp at a U.S. Consulate, preferably in your home country, and seek reentry to the U.S. in H-4 status. You should carefully consider whether international travel is the best option based on your personal situation, considering such factors as ability to travel, wait times at the U.S. Consular post, the status of the principal beneficiary, and others.
You can find the Form I-539/I-539A and instructions to the Form on the USCIS website.