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CO-40 Denial Code: Not Qualified as Emergent or Urgent Care

CO-40 means the payer determined the charges don't meet its qualifications for emergency or urgent care, so it won't pay them at emergency or urgent benefit levels or at all. Review the diagnosis coding, place of service, and documentation, then correct or appeal.

Quick facts

Code
CO-40 (CARC 40)
Status
Active In use since January 1, 1995; last modified July 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The usual group. The provider absorbs the denied amount unless the claim is corrected or the denial is overturned.
  • PR (Patient Responsibility): Used when the payer assigns the cost to the patient, for example at non-emergency benefit levels. Federal and state rules on emergency services may limit what the patient can be charged.
Official description
Charges do not meet qualifications for emergent/urgent care. Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-40 means

CARC 40 says charges do not meet qualifications for emergent or urgent care. The payer reviewed a claim billed as an emergency or urgent visit and decided the situation didn’t qualify under its criteria. Depending on the plan, that can mean a full denial, processing at a lower non-emergency benefit, or a requirement for authorization that emergencies would otherwise be exempt from.

The usage note points to the 835 Healthcare Policy Identification segment. If the payer lists a policy there, it’s often an emergency department review or diagnosis-screening policy that you’ll need to address in an appeal.

Federal law and many state laws apply the prudent layperson standard to emergency services: coverage depends on whether a reasonable person would have believed they needed immediate care based on their symptoms, not on the final diagnosis. Payers still issue CO-40, but that standard is often the core of a successful appeal.

Common causes

  • Final diagnosis looks minor, even though presenting symptoms were concerning.
  • Symptom codes omitted, so only the final benign diagnosis appears in box 21.
  • Emergency records not sent when the payer requested them.
  • Urgent care billed with the wrong place of service or visit type.
  • Out-of-network facility where the payer is testing whether emergency protections apply.

How to fix it

  1. Read the remark code and policy reference to see which criteria the payer applied.
  2. Review coding. Make sure documented presenting symptoms, not just the final diagnosis, are reported where coding guidelines allow.
  3. Check the place of service in box 24B and the visit type billed.
  4. Send a corrected claim (resubmission code 7 in box 22) if coding or POS was wrong.
  5. Appeal with the triage notes, vitals, history of present illness, and physician assessment, and reference the prudent layperson standard.
  6. Check patient billing rules before billing any PR amount, since emergency services may carry balance-billing protections.

How to prevent it

  • Document presenting symptoms and acuity clearly in the record.
  • Code symptoms as well as final diagnoses when guidelines support it.
  • Know each payer’s emergency review policies and records requirements.
  • Send records promptly when requested.

Specialty notes

Emergency medicine groups and urgent care centers see CO-40 most. Urgent care centers should confirm how each payer classifies urgent care visits, since some treat them like office visits and others as a separate benefit.

Remark codes that may appear with CO-40

  • N391 (Missing emergency department records.): Emergency department records are missing, so the payer couldn't evaluate urgency.
  • N392 (Incomplete/invalid emergency department records.): The emergency department records were incomplete or invalid.
  • N864 (Alert: This claim is subject to the No Surprises Act provisions that apply to emergency services.): The claim is subject to No Surprises Act provisions for emergency services.
  • CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Not medically necessary, a broader denial not tied to the emergency qualification.
  • CO-58 (Treatment was deemed by the payer to have been rendered in an inappropriate or invalid place of service.): Treatment rendered in an inappropriate place of service.
  • CO-197 (Precertification/authorization/notification/pre-treatment absent.): Authorization absent, which may apply if the payer decides the visit wasn't an emergency.
  • CO-242 (Services not provided by network/primary care providers.): Services not provided by network providers, often linked to non-emergency out-of-network care.

CO-40 FAQ

What is the prudent layperson standard?

It's a standard used in federal law and many state laws: a condition is an emergency if a person with average knowledge of health and medicine would reasonably expect that the symptoms needed immediate care. Coverage is judged by presenting symptoms, not only the final diagnosis.

How do I appeal CO-40?

Send the emergency department or urgent care records showing the presenting symptoms, triage notes, and why immediate care was needed. Cite the prudent layperson standard where it applies.

Can a diagnosis code cause CO-40?

Yes. Some payers screen emergency claims by final diagnosis. Listing the presenting symptom codes that were documented, along with the final diagnosis, can help show urgency.