Student
F-1, M-1, J-1
Financial documents incomplete or inconsistent
The most common document-request 221(g) for students. Bank statements not covering enough months, sponsor affidavits not matching what you said verbally, loan sanction letters pending at the time of interview. Officers ask for the complete set when the file has a gap.
I-20 or SEVIS verification
Mismatches between the I-20 you carried, the DS-160 you filed, and the SEVIS record. Often requested when the program start date, funding source, or school address don't align perfectly across documents.
Transcripts or degree verification
For applicants from certain universities or with unusual academic trajectories, officers may request original transcripts or a credentials evaluation before issuing the visa.
Source of funds clarification
When large recent deposits show in bank statements without a clear income source, officers may request additional paperwork explaining where the funds came from.
Security-related administrative processing
Less common for students, but applicants with backgrounds in certain sensitive technical fields (nuclear, advanced materials, dual-use research) can trigger AP for technology-alert review.
The biggest single factor
For students, the most common 221(g) trigger is financial documentation that didn't come together neatly at the interview. Having everything organized, current, and consistent is the single best prevention.