As you know, a foreign national who is physically present in the U.S. and the spouse of a U.S. citizen can generally apply for a green card without leaving the U.S. This process, known as Adjustment of Status, concludes with an interview. The USCIS interviews virtually every applicant for a marriage-based green card. 

Upon completing a successful marriage-based adjustment of status interview, the applicant will generally become a permanent resident (green card holder). Every couple should prepare for this interview. Knowing what to expect, what items to take, and how to respond to questions will improve your chances of approval.

After filing a marriage-based Form I-485, Application to Adjust Status, there are generally two appointments. USCIS will schedule a biometrics appointment for the applicant (usually within the first couple of months) and then the interview appointment many, many months later. USCIS requires both spouses (the applicant and petitioner) to attend the marriage-based adjustment of status interview.