Denial codes
Dental denial codes in plain English.
The codes on an insurer's explanation of benefits tell you why a claim was cut or denied. Each page below says what the code means for a dental office, what usually causes it, what to send, and how to stop it next time.
First, the two letters in front
CO- Contractual obligation: the office cannot bill the patient for this amount.
PR- Patient responsibility: the patient may owe this amount.
OA- Other adjustment: neither CO nor PR applies.
PI- Payer-initiated reduction.
CR- Correction or reversal of an earlier claim.
- PR-1Deductible
- PR-2Coinsurance
- PR-3Co-payment
- CO-16Missing or incorrect information
- CO-18Duplicate claim
- CO-22Another insurer should pay first
- CO-23Adjusted for the other insurer's payment
- CO-26Before coverage started
- CO-27After coverage ended
- CO-29Filing deadline passed
- CO-31Patient not found as a member
- PR-35Lifetime maximum reached
- CO-45Above the contracted fee (PPO write-off)
- CO-50Not considered medically necessary
- CO-96Not covered
- CO-97Bundled into another procedure
- CO-107Related claim not identified
- CO-109Wrong insurer
- CO-119Benefit maximum reached
- CO-151Too many services (frequency)
- CO-167Diagnosis not covered
- CO-197No pre-authorization
- CO-204Not covered under the current plan
- CO-226Requested information not sent
- CO-242Out-of-network provider
- CO-252Attachment required
- CO-B7Provider not eligible on this date
Have a pile of these? Drop your outstanding-claims report into the free check. It groups every claim by code, ranks them by dollars and deadline, and drafts the letters. Nothing leaves your computer.
Plain-English paraphrases for office staff. The official Claim Adjustment Reason Code list is maintained by X12 (x12.org). Insurer rules vary; check each insurer's provider manual.