The National Visa Center (NVC) ensures that all the family-based green card applications going through consular processing are ‘documentarily qualified’ (‘DQ’), also known as ‘documentarily complete’ or ‘interview-ready’. It does not make decision on the application; the consular officer will. The NVC is a unit of the Department of State, not USCIS.
The following table describes the National Visa Center (NVC) ‘pre-processing’ of family Green Card cases from the moment the approved I-130 is received from USCIS to the time when the applicant’s case is sent to the U.S. Consulate or Embassy abroad for interview: