First off, it is necessary to get assurance that both participants of future intermarriage are eligible to register a marriage. It is necessary to start by filling in the Form I-129F. After paying for all the necessary fees related to paperwork and medical exam, the USCIS will review the application, conduct background checks, and make a decision. In case of a successful visa issue, it is necessary to get married to a foreign spouse within 90 days after she enters the US.