CO 216 denial code

Claim adjustment reason code 216. Often reported as CO 216.

Based on a review organization's findings

Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated Nov 11, 2026.

What 216 means

The payment was adjusted because of what a review organization, or the payer acting in that role, found on review.

A utilization review, quality review or similar review body looked at the claim or the care and found a reason to reduce or deny payment.

The code says who made the call, not why. Look at remark codes and any review letter for the specific finding.

Group codes seen with 216

On a remittance, 216 comes after a group code. These are the ones it is most often reported with:

• CO 216 (Contractual Obligation): The provider's side of the ledger. The reduction comes from the payer contract or a rule the provider has to follow, and the patient normally cannot be billed for it.

The payer chooses the group code for each adjustment, so the same reason code can appear with another group code on your remittance. Read the two together. More about group codes.

Common causes

• A medical necessity review found part of the stay or service was not needed.
• A quality or utilization review found the level of care was higher than needed.
• A post-payment audit led to a recoupment or adjustment.

What to do next

1. Get the review organization's letter or findings for the claim.
2. Compare the findings with the medical record before deciding whether to appeal.
3. Follow the review organization's own appeal path if it differs from the payer's.
4. Share recurring findings with clinical teams so documentation improves.

Related codes

• 50 (reason code) Not medically necessary per the payer
• 193 (reason code) Original decision upheld after review
• 249 (reason code) Claim flagged as a readmission