Central Index System (CIS)
Central Index System (CIS) is USCIS’ main database, containing biographical and status information of applicants seeking immigration and non-immigration benefits.Footnote 1 CIS’ main purpose is to provide a searchable central index of “alien files,” or A-Files — physical files that contain hard copy documents that detail a person’s current immigration status.Footnote 2
Data in CIS is riddled with errors such as name misspellings and incorrect nationalities listed.Footnote 3 DHS acknowledged in a 2012 study that at least 12% of individuals had the wrong “admission field,” which is often caused by an officer failing to update a person’s immigration status when it changes.Footnote 4 The CIS database is the “spine” of USCIS’s functions.Footnote 4