Denial codes

Denial codes, decoded

Every denial on your EOB comes with a standardized code. The codes are cryptic by design, but each one has a specific meaning, a responsible party, and a fix. Find yours below.

Medical Necessity & Clinical

CO-50Not Medically Necessary
CO-55Experimental or Investigational
CO-56Not Proven Effective
CO-150Level of Service Not Supported
CO-151Frequency of Services Not Supported

Prior Authorization

CO-197No Prior Authorization
CO-15Authorization Number Missing or Invalid
CO-39Authorization Denied Before Service
CO-288Referral Absent
CO-198Authorization Exceeded

Administrative & Billing Errors

CO-16Missing Information / Billing Error
CO-18Duplicate Claim
CO-29Timely Filing Expired
CO-4Modifier Issue
CO-11Diagnosis Doesn't Match Procedure
CO-199Revenue and Procedure Code Mismatch
CO-31Patient Not Identified

Coverage & Benefits

CO-96Non-Covered Charges
PR-204Not Covered Under Benefit Plan
PR-27Coverage Terminated
CO-167Diagnosis Not Covered
CO-119Benefit Maximum Reached
PR-26Expenses Before Coverage Began
PR-49Routine Exam Not Covered
PR-51Pre-Existing Condition
CO-242Not a Network Provider

Coordination of Benefits

CO-22Coordination of Benefits
OA-23Prior Payer Adjudication
OA-24Covered by a Managed Care Plan
CO-109Wrong Payer

Contractual & Payment Rules

CO-45Charge Exceeds Fee Schedule
CO-97Bundled Into Another Service
CO-59Multiple Procedure Reduction
CO-236Same-Day Procedure Conflict (NCCI)

Cost Sharing (Your Share)

PR-1Deductible Amount
PR-2Coinsurance Amount
PR-3Copayment Amount

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