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CARC
CO-16
CARC
CO — Contractual Obligation
Coding/Modifier
Quick Facts
Code
CO-16
Type
CARC
Category
Coding/Modifier
Status
Active
Claim lacks information needed for adjudication
What Does This Code Mean?
The claim or service was denied because it is missing information, or has submission/billing errors that prevent the payer from processing it. This is one of the most common front-end denial codes and is almost always paired with a RARC that names the specific missing item.
Common Causes
- Missing or invalid modifier
- Missing referring provider NPI
- Incomplete diagnosis pointer
- Missing prior authorization number field
Recommended Next Steps
- Check the accompanying RARC (e.g. M51, N286) to identify exactly what's missing
- Correct the claim field noted by the remark code
- Resubmit as a corrected claim, not a duplicate
- Verify clearinghouse edits are catching this before submission going forward
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Educational reference only — not medical or legal advice. Always confirm code usage and appeal rights with the specific payer.