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Requirements for K4 Classification
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4. To qualify for K4 issuance, an applicant must be the minor, unmarried child under 21 years of age of a qualified K3 applicant. The USCIS rule notes that the U.S. citizen who files an I-129F petition for an alien spouse does not have to file a separate I-129F petition for a child of that spouse. These children are to be listed on the I-129F petition for the spouse.
我理解得对吗?