K-1 Visa Holder (Fiancé(e) of U.S. Citizen)
If you enter the United States on a K-1 visa, you are required to marry within 90 day of your arrival. After the marriage ceremony has taken place, you will be required to apply for an adjustment of status from nonimmigrant to conditional resident with the U.S. Citizenship and Immigration Services (USCIS). Conditional residence is granted for a two-year period.
If you marry and then leave the United States for a holiday or visit abroad, you must obtain advance parole from USCIS before departing the country. If you do not obtain Advanced Parole, you will require an immigrant visa in order to return to the United States; this will take approximately 10-12 months to process.
K-3 and K-4 Visa Holder (Spouse and child of a U.S. Citizen)
If you hold a K-3 visa, you will be admitted into the United States for a two year period to await the issuance of an immigrant visa. Children holding K-4 visas will be admitted for two years or until the day before their twenty-first birthday, whichever is shorter. Should the I-130 petition be denied or revoked by USCIS, your status will terminate 30 days later. Your status will also terminate if you divorce, or in the case of a K-4 visa holder, turn 21 or get married.
Working on a K visa
USCIS may grant permission for the holder of a K visa to take up employment in the United States. Information is available from their website, www.uscis.gov