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CO-291 Denial Code: Medical Plan Forwarded Claim to Dental

CO-291 means the patient's medical plan received the claim, found no medical benefit for the service, and forwarded it to the patient's dental plan. The dental plan will adjudicate it under dental rules, so wait for its response before resubmitting.

Quick facts

Code
CO-291 (CARC 291)
Status
Active In use since November 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The usual group. The medical plan pays nothing, and the amount isn't billable to the patient while the dental plan reviews the claim.
  • OA (Other Adjustment): Some payers use OA since the claim is being transferred rather than finally denied.
Official description
Claim received by the medical plan, but benefits not available under this plan. Claim has been forwarded to the patient's dental plan for further consideration.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-291 means

CARC 291 says the claim was received by the medical plan, but benefits are not available under this plan, and the claim has been forwarded to the patient’s dental plan. The medical carrier decided the service is dental in nature and routed it to the member’s dental coverage.

X12’s note says to use CARC 270 when the medical plan doesn’t forward the claim. With CO-291, the claim should already be on its way, so the next step is follow-up rather than resubmission.

Keep in mind that the dental plan evaluates services very differently. Dental benefits usually have low annual maximums, frequency limits (for example, how often a cleaning or crown is covered), waiting periods, and missing-tooth clauses. A service that crossed over from medical may come back with substantial patient responsibility.

Common causes

  • Dental procedures billed on a medical claim by a hospital, surgery center, or physician.
  • Medical plan dental exclusions, which commonly exclude routine dental care outside narrow exceptions such as accidental injury.
  • Integrated administrators that route claims between medical and dental benefits automatically.

How to handle it

  1. Hold the balance and don’t bill the patient yet.
  2. Check the dental plan’s claim status after a reasonable interval.
  3. Be ready to supply dental detail, including CDT codes, tooth numbers, surfaces, quadrants, and radiographs, since a medical claim won’t carry these.
  4. If the dental plan has no record, submit a dental claim directly (ADA form or 837D), keeping the medical remittance as proof of original filing.
  5. If the service was medical, for example related to an accident or a medical condition, appeal to the medical plan with records showing the medical basis.

How to prevent problems

  • Screen for dental services before billing medical plans and verify dental coverage in advance.
  • Know each medical plan’s dental exceptions, such as accidental injury or hospital-setting coverage for certain patients.
  • Use the right claim form and code set for the plan you bill.
  • Track forwarded claims until the receiving plan responds.

Specialty notes

Hospitals and ambulatory surgery centers that host dental procedures under anesthesia often see CO-291 on the professional dental service, while the facility and anesthesia charges may remain under medical review with their own rules.

Remark codes that may appear with CO-291

  • N130 (Consult plan benefit documents/guidelines for information about restrictions for this service.): Points to the medical plan's documents that exclude dental services.
  • CO-270 (Claim received by the medical plan, but benefits not available under this plan.): The medical plan found no benefit but did not forward the claim; you must submit it to the dental plan.
  • CO-290 (Claim received by the dental plan, but benefits not available under this plan.): The reverse: a dental plan forwarded the claim to the medical plan.
  • CO-289 (Services considered under the dental and medical plans, benefits not available.): Both medical and dental plans considered it; no benefits available.
  • CO-292 (Claim received by the medical plan, but benefits not available under this plan.): The medical plan forwarded the claim to a pharmacy plan instead.

CO-291 FAQ

What happens after the dental plan gets the forwarded claim?

The dental plan applies its own rules: CDT codes, annual maximums, frequency limits, waiting periods, and its own network. It may ask for tooth numbers, surfaces, or X-rays that weren't on the medical claim.

Should I resubmit to the dental plan?

Not immediately. X12 uses CARC 291 only when the claim was forwarded. Check the dental plan's claim status first; resubmit only if it has no record, to avoid duplicates.

Which services usually cause CO-291?

Routine dental services billed to a medical plan, such as extractions, restorations, or dental cleanings, especially from hospital or facility settings or when a medical biller wasn't aware the service was dental.

Can the patient be billed?

Wait for the dental plan's decision. Patient responsibility will come from the dental remittance, such as coinsurance or amounts over the annual maximum.