CO-16Contractual ObligationDocumentation
CO-16 Denial Code: Claim lacks information or has submission error
The claim/service lacks information or has a submission/billing error needed for adjudication. Usually accompanied by an RARC remark code identifying the missing element.
Why CO-16 happens
- ●Missing or invalid NPI, taxonomy, or member ID
- ●Missing remark-code-specified data (e.g., NDC, referring provider)
- ●Incomplete claim fields or attachment not received
How to fix a CO-16 denial
- 1
Read the accompanying RARC remark code to identify the exact missing item
- 2
Correct or supply the missing information
- 3
Resubmit as a corrected claim — do not appeal
How to prevent it
Tighten front-end claim scrubbing rules for the specific remark codes you see most.
Drowning in CO-16 denials?
OakClaim works every denial within 48 hours and builds prevention rules so they stop recurring.