CO 16: Missing Claim Information
Something the payer needed was missing or wrong on the claim.
Read the RARC beside it; that names the missing item. Correct and resubmit.
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What CO 16 means
CO: Contractual obligation. The provider absorbs it and cannot bill the patient.
So the balance cannot move to the patient. Either the appeal recovers it or the practice absorbs it. That makes the appeal decision the whole decision on this line.
The same code, a different prefix. 16 also arrives as PR 16. The reason for the denial is the same. The prefix decides who pays for it, so the next step is not the same. If your remit says PR 16, read that page instead.
Is It Worth Appealing?
Fix and resubmit. This is a correction, not an appeal. Appealing burns the deadline.
Why It Fires
In the order we see it.
The RARC printed beside this code names the actual missing item.
A missing or invalid NPI, referring provider, modifier or accident date.
How to Fix CO 16, Step by Step
Read the RARC beside it; that names the missing item. Correct and resubmit.
- 1Step 1: Read the remark code. Find the remark code printed next to CO 16 on the 835 or EOB. It says what the payer wants back. The usual ones are N56, N59, N822.
- 2Step 2: Find the cause. Match the denial to one of the 2 causes in Why It Fires above, and fix that one.
- 3Step 3: Do this. Read the RARC beside it; that names the missing item. Correct and resubmit.
- 4Step 4: Attach the documentation. A corrected claim with the missing element supplied.
The common mistake. Do not appeal this. It is a correction, and an appeal spends the timely-filing clock on a claim that would have paid on resubmission.
Free: the Denial Code Appeal Playbook. 53 codes on one sheet: appeal, fix and resubmit, or let it go, and what to attach. Get the playbook
CO 16 description
Something the payer needed was missing or wrong on the claim.
Something the payer needed was missing or wrong on the claim. So the balance cannot move to the patient. Either the appeal recovers it or the practice absorbs it. That makes the appeal decision the whole decision on this line.
This is our plain-English wording, not the official X12 text. X12 asserts copyright over the published descriptions, so we write our own and say what it means for the money rather than restating the code.
Where this comes from. This is our own reading of the code, not the payer's and not a copy of the standards text. We classify it from how these denials actually resolve. Where we are unsure, we say so rather than guessing.
The Remark Code Beside It
The adjustment code says the claim was reduced. The remark code printed next to it says why, and it is the one that tells you what to send back.
| Remark | What it means |
|---|---|
| N56 | The procedure code does not match what was done, or was not valid on that date of service. |
| N59 | The payer has pointed you at the provider manual rather than naming the rule it applied. |
| N822 | A modifier the payer needed was missing from the procedure. |
| N290 | The rendering provider identifier is missing, incomplete or wrong. |
| MA130 | The claim was unprocessable, so it was never adjudicated and carries no appeal rights at all. |
| N211 | The payer is telling you this particular decision carries no appeal rights. |
| M51 | A procedure code is missing, incomplete or not valid. |
| N706 | The payer says a document it needed never arrived. |
| MA63 | The principal diagnosis is missing, not coded to full specificity, or not valid on the date of service. |
| N517 | The payer is asking for a new claim that includes the information it requested. |
| N265 | The NPI of the provider who ordered the service is missing, incomplete or wrong. |
Related Codes
Your Questions Answered
What does CO 16 mean?
Something the payer needed was missing or wrong on the claim. Contractual obligation. The provider absorbs it and cannot bill the patient.
Can you appeal CO 16?
Fix and resubmit. Read the RARC beside it; that names the missing item. Correct and resubmit.
Why does CO 16 happen?
The RARC printed beside this code names the actual missing item. A missing or invalid NPI, referring provider, modifier or accident date.
What documentation wins a CO 16 appeal?
A corrected claim with the missing element supplied.
How do I fix a CO 16 denial?
Step 1: Read the remark code. Find the remark code printed next to CO 16 on the 835 or EOB. It says what the payer wants back. Step 2: Find the cause. Match the denial to one cause: The RARC printed beside this code names the actual missing item. A missing or invalid NPI, referring provider, modifier or accident date. Step 3: Do this. Read the RARC beside it; that names the missing item. Correct and resubmit. Step 4: Attach the documentation. A corrected claim with the missing element supplied.
Most searched: CO 97 · CO 96 · OA 23 · PR 204 · CO 109 · CO 197 · CO 45 · CO 50
How Much of This Is Sitting in Your Write-Off Pile?
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