CO-A8Contractual ObligationCoding
CO-A8 Denial Code: Ungroupable DRG
The claim's data couldn't be grouped to a valid DRG — something in diagnoses, procedures, or demographics breaks the grouper.
Why CO-A8 happens
- ●Invalid principal diagnosis for grouping
- ●Sex/age conflicts with the coded conditions
- ●Missing required procedure data
How to fix a CO-A8 denial
- 1
Run the claim through your grouper to find the failing element; correct and rebill
How to prevent it
Pre-bill DRG grouping validation on all inpatient claims.
Drowning in CO-A8 denials?
OakClaim works every denial within 48 hours and builds prevention rules so they stop recurring.