CO-296 denial code
Authorization number may be valid but does not apply to the provider
How to fix it
Confirm which provider the authorisation names and request an amendment or a new authorisation.
How to prevent it
Authorisations are provider-specific. A group authorisation does not automatically cover every rendering provider.
In practice
A group obtains authorisation for a procedure naming one surgeon. Scheduling moves the case to a colleague, the procedure goes ahead, and the claim returns CO-296.
Authorisations are provider-specific unless issued to a group. An authorisation naming an individual does not automatically extend to a partner, however identical the service and the setting.
Request an amended authorisation naming the provider who actually performed the service. Where the substitution was unavoidable, most plans will amend, but the request has to be made rather than assumed.
What sits behind it
Coverage substitutions are the recurring cause: illness, emergency cover, call rotations and last-minute schedule changes all move cases between providers after authorisation is obtained, and the authorisation does not move with them.
Where a plan issues group-level authorisations, this problem largely disappears, and it is worth establishing which of your payers do. The answer determines whether a schedule change needs an administrative step or not.
The locum tenens arrangements that cover absent physicians have their own billing rules and modifiers, and using them correctly can resolve what otherwise looks like a provider mismatch. That is a different mechanism from amending the authorisation and applies to a narrower set of situations.
Related codes
Terms used here — Prior Authorization · Credentialing · Modifier
How we handle it — Prior Authorization · Provider Credentialing · Denial Management
Primary sources
The rules behind CO-296, at the bodies that publish them.
- CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F) (opens in a new tab)
Centers for Medicare & Medicaid Services — The rule imposing prior authorization decision timelines and API requirements on impacted payers. It is the single largest scheduled change to authorization workflow this decade.
- Medicare Coverage Database (LCD/NCD) (opens in a new tab)
Centers for Medicare & Medicaid Services — Searchable national and local coverage determinations. The direct answer to whether a diagnosis supports medical necessity for a given procedure.
- 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-296
Only where the plan issues it at group level, which some do and some do not. An authorisation naming an individual does not extend to a colleague automatically, so establishing which of your payers authorise by group is worth doing once.
Request an amendment naming the provider who actually performed the service. Most plans accommodate unavoidable substitutions — illness, emergency cover, call rotation — but the request has to be made rather than assumed.
In a narrower set of situations, yes. Locum arrangements have their own billing mechanism and modifier, and used correctly they can resolve what otherwise reads as a provider mismatch. They are not a general substitute for amending an authorisation.
Find out what your denials are costing you
A free billing audit reviews your denial rate, AR aging and clean claim rate against industry benchmarks. Takes about two minutes to request. No sales pitch.
No setup fees · You pay when we collect · Pricing from 3% of net collections