CO 115 denial code

Claim adjustment reason code 115. Often reported as CO 115.

Procedure postponed, canceled or delayed

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 115 means

The payer adjusted the claim because the procedure was postponed, canceled or delayed.

The claim shows a procedure that did not happen as planned. The payer is not paying, or is paying differently, because the service was stopped, put off or not done on the billed date.

Many payers have specific modifiers or rules for procedures discontinued before or after anesthesia. Check how the claim reported the cancellation.

Group codes seen with 115

On a remittance, 115 comes after a group code. These are the ones it is most often reported with:

• CO 115 (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

• The procedure was canceled before it started and was billed as if completed.
• The surgery was stopped partway and the right reduced service modifier was missing.
• The procedure was rescheduled and the claim used the original date.

What to do next

1. Check the record to see whether and when the procedure was performed.
2. Use the payer's modifiers for reduced or discontinued services and resubmit if appropriate.
3. Correct the date of service if the procedure took place on a different day.

Related codes

• 16 (reason code) Missing information or billing error
• 4 (reason code) Procedure code and modifier do not match