CO-299 denial code
The billing provider is not eligible to receive payment for the service billed
How to fix it
Verify the billing provider's enrolment and the service's payability under that enrolment.
How to prevent it
Usually an enrolment or taxonomy configuration issue requiring correction at the payer.
In practice
A practice adds a new service line and begins billing it. The payer returns CO-299, because the billing entity's enrolment does not cover services of that type.
The provider is enrolled and the service is covered. What fails is that this enrolment does not authorise payment for this category of service, which is a configuration boundary rather than a coverage question.
Verify what the enrolment actually permits and whether it needs extending. Adding a service line frequently requires an enrolment update that nobody thinks of until claims start denying.
What sits behind it
Enrolment records carry more structure than a single active flag. Specialty designation, service categories, locations and certifications each form part of what an entity may be paid for, and each can be incomplete.
New service lines are the classic trigger. A practice adding laboratory testing, imaging, therapy or equipment supply is entering a category its enrolment may never have covered, and the requirement usually surfaces through denials rather than through a checklist.
The correction takes time at the payer while the filing deadline runs, which makes early submission important. Claims held pending an enrolment update can age past the window and become unrecoverable even after the configuration is right.
Related codes
Terms used here — Credentialing · NPI · Timely Filing
How we handle it — Provider Credentialing · Denial Management · Revenue Cycle Management
Primary sources
The rules behind CO-299, at the bodies that publish them.
- PECOS Medicare enrollment (opens in a new tab)
Centers for Medicare & Medicaid Services — Where Medicare provider enrollment is filed and maintained. Revalidation deadlines missed here stop payment outright.
- NPI Registry (NPPES) (opens in a new tab)
Centers for Medicare & Medicaid Services — Public lookup and management for National Provider Identifiers. A stale NPPES record is a quietly common cause of enrollment and claim rejections.
- Medicare Claims Processing Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — The operative manual for how Medicare claims must be coded, submitted, adjusted and appealed. When a payer policy and a vendor's advice disagree, this settles it.
Looking for a different code? Search all 190 CARC and RARC codes
Questions about CO-299
Because enrolment carries structure beyond an active flag — specialty designation, permitted service categories, locations and certifications. A provider correctly enrolled for one category can be unenrolled for another, and the claim fails on that boundary.
Adding a new service line. A practice starting laboratory testing, imaging, therapy or equipment supply enters a category its enrolment may never have covered, and the requirement surfaces through denials rather than through any prompt.
No. The filing deadline runs throughout and updates take weeks, so held claims can age past the window and stay unrecoverable even after the configuration is corrected. Submit to preserve the date and appeal on the corrected record.
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