N823N-series (general use)Missing Information
N823: Procedure modifier invalid
A modifier on the claim is invalid, deleted, or inconsistent with the procedure code it's attached to.
Commonly appears with these denial codes
The denial code gives the category; N823 pinpoints the specific problem. Read them together before touching the claim.
What to do about it
Remove or replace the invalid modifier, checking effective dates after quarterly updates, and resubmit.
OakClaim fixes root causes, not just claims.
Free billing audit shows which remark codes keep recurring in your AR — and what they're costing you.