Overview: F3 covers married sons and daughters of U.S. citizens. F4 covers siblings of U.S. citizens, and requires the petitioning citizen to be at least 21 years old. F4 is generally the most backlogged family preference category, often carrying waits measured in decades for high-demand countries, considerably longer than F3's typically shorter, though still substantial, wait.
Who qualifies under F3
F3 covers the married son or daughter of a U.S. citizen, at any age, along with that son or daughter's spouse and unmarried minor children as derivative beneficiaries.
Who qualifies under F4
F4 covers the brother or sister of a U.S. citizen, but only where the petitioning citizen is at least 21 years old, along with the sibling's spouse and unmarried minor children as derivatives.
Why F4 typically carries the longest wait of any family category
F4 receives a smaller annual allocation relative to demand than most other family categories, and sibling relationships are a step further removed than parent-child relationships in the priority Congress assigned across the preference system, which is part of why F4 waits, particularly for high-demand countries, have historically run longer than any other family preference category.
How derivative family members factor into each category
Both F3 and F4 allow the principal BeneficiaryThe person on whose behalf a petition is filed, such as the relative or worker who would receive the immigration benefit.See it in the glossary's spouse and unmarried minor children to immigrate together as derivatives once a visa becomes available, though those derivative children remain subject to the same Child Status Protection Act (CSPA)A federal law that changes how age is calculated for certain children in the green card process, so a child who turns 21 while a case is pending may still be treated as a child. The result is called the CSPA age. For adjustment of status applications filed on or after August 15, 2025, USCIS treats a visa as available based on the Final Action Dates chart in the Visa Bulletin.See it in the glossary age calculations as any other Derivative beneficiaryA spouse or unmarried child under 21 who can immigrate with, or follow to join, a principal applicant under the same petition.See it in the glossary.
Why the citizen petitioner's age matters for F4 specifically
Unlike most family categories, F4 has an age floor for the PetitionerThe person or employer who files a petition on behalf of a beneficiary, such as a relative filing an I-130 or an employer filing an I-140.See it in the glossary: a U.S. citizen cannot petition for a sibling until they turn 21, which can delay when an eligible petition can even be filed in situations where the citizen sibling is still a minor.
Setting realistic expectations for either category
Given how long both categories, and F4 in particular, can take depending on the beneficiary's country of birth, checking current Visa BulletinA monthly State Department publication showing which family and employment visa categories currently have visas available.See it in the glossary movement for the specific category and country is essential to setting a realistic timeline rather than relying on a general sense of how family immigration works.
Official sources
Related reading
- The Family Preference Categories
- F1 vs. F3: Unmarried vs. Married Sons and Daughters of U.S. Citizens
TR Immigration is an independent immigration information platform. It is not a law firm. Nothing here is legal advice, an eligibility determination, or a prediction about your case. Rules and fees change often, so confirm anything you rely on against the official page it links to.