For U.S. citizen parents raising children abroad, Form N-600K has a built-in deadline: the child’s 18th birthday. Unlike many immigration deadlines, this one is not about when you file. It is about when the process ends, and families who start late can run out of time.

Why the birthday controls

INA 322, 8 U.S.C. 1433, lists the conditions USCIS must find satisfied, including that the child is under the age of eighteen. Under subsection (b), the child becomes a citizen only upon approval of the application and the oath of allegiance. The conditions, including age, therefore have to be met when the case is completed, not just when it is filed.

How USCIS counts the day

The USCIS Policy Manual says USCIS considers a child to be under 18 until the end of the day on the child’s 18th birthday. That is the last possible day. In its September 2026 policy alert on deadlines, USCIS also made clear that deadlines tied to a birthday do not move to the next business day; see our summary.

The travel and status requirement

Section 322 requires the child to be temporarily present in the United States after a lawful admission and to maintain that status. In practice the family must plan a trip for the interview and oath, often with a visitor visa or visa waiver, and keep the child in status during the stay. Children of members of the armed forces abroad on official orders are excepted from this requirement and may take the oath abroad.

Interviews and the oath

The Policy Manual explains that USCIS may waive the interview when the required documentation is already in its records or submitted with the application. The oath generally must be taken in the United States unless waived. n600k.com explains how to plan the interview trip and answers common questions in its N-600K FAQ.

Building a timeline

  • File as early as possible, ideally years before the 18th birthday.
  • Collect physical presence evidence first; see the physical presence rules.
  • Keep the child’s passport and visa valid for travel.
  • If the case stalls as the birthday approaches, act quickly; see N-600K delays and n600k.com on aging out.

For the choice between forms, see N-600 vs. N-600K.

Frequently asked questions

Is filing before 18 enough? No. Under INA 322 the child becomes a citizen upon approval and the oath, and the age condition must still be met then.

What happens if the child turns 18 first? The child can no longer use section 322 and would need a different path to citizenship.

Can the interview be skipped? USCIS may waive it when the documentation is already in its records or submitted with the application.

Key Takeaways

  • Under INA 322 the child must still be under 18 when the case is approved and the oath is taken.
  • USCIS treats a child as under 18 until the end of the 18th birthday.
  • Birthday-based deadlines do not move to the next business day.
  • The child must be temporarily present in the United States in lawful status, except certain military children.
  • Start early and act fast if the case stalls near the birthday.

Disclosure: This site collaborates with the law firm that publishes mandamus.com and n600k.com; some articles link to their guides. General information only, not legal advice.

General information only, not legal advice. Immigration law and agency policy change often; confirm current rules before acting. Published October 26, 2026. Official sources checked October 26, 2026.