CO 40 denial code

Claim adjustment reason code 40. Often reported as CO 40 or PR 40.

Did not meet emergency or urgent criteria

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 40 means

The payer decided the service did not qualify as emergency or urgent care, so it was not paid at that level.

The claim was billed as emergency or urgent care, but the payer's review, often based on the final diagnosis, decided the visit did not meet its criteria. The claim may be denied or processed under a lower benefit.

Many payers must consider the symptoms the patient had on arrival, not only the final diagnosis, so the record is key in an appeal. The line may carry a payer policy identifier, which is the quickest way to see which rule was applied.

Group codes seen with 40

On a remittance, 40 comes after a group code. These are the ones it is most often reported with:

• CO 40 (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.
• PR 40 (Patient Responsibility): The amount is assigned to the patient. Deductibles, coinsurance and copays are the everyday examples. Whether you can collect it still depends on your contract and the patient's plan.

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 final diagnosis looked minor even though the presenting symptoms were serious.
• The diagnosis codes on the claim did not reflect the symptoms that brought the patient in.
• The payer applied a list of diagnoses it does not consider emergencies.

What to do next

1. Review the record for the presenting symptoms and triage notes.
2. Add any symptom diagnoses that were documented and send a corrected claim if they were missed.
3. Appeal with the triage notes and records showing why a reasonable person would seek emergency care.
4. Check the payer's emergency care policy before deciding how to bill the balance.

Related codes

• 39 (reason code) Authorization was requested and denied
• 50 (reason code) Not medically necessary per the payer
• 11 (reason code) Diagnosis does not support the procedure