120 Denial Code (Deactivated) – Use 24

120 is a retired claim adjustment reason code. Payers stopped using it on 06/30/2007. Current remittances use 24 instead.

Seeing 120 on a Remittance?

120 was retired effective 06/30/2007 and should not appear on new remittances.
Payers now report this situation with 24 — check that page for current guidance.
Official retirement note: Use code 24.
If 120 appears on an old ERA you are reworking, interpret it per the remittance date, then follow the current code's guidance for any corrected claim.