CO-226 denial code
Information requested from the billing or rendering provider was not provided or was insufficient
How to fix it
Locate the original request and respond with exactly what was asked, referencing the claim.
How to prevent it
Log payer information requests centrally with due dates. Unanswered requests become permanent denials.
In practice
A payer sends a records request by post. It arrives during a staffing gap, is filed without action, and the claim returns CO-226 six weeks later for an unanswered request.
The payer asked for something and received nothing. From its perspective the claim is unsupported, and it will remain so until the information arrives.
Find the original request before responding, because sending the wrong documents produces CO-250 and starts the cycle again. Respond to exactly what was asked, referencing the claim, and confirm receipt.
What sits behind it
The root cause is nearly always routing rather than refusal. Requests arrive by post, portal message, fax and electronic transaction, and where no single person owns them across all channels, some go unread until a denial surfaces them.
A central log with an owner and a due date for every request is the control that works. It also makes the aggregate visible: practices that build one frequently discover they are receiving far more requests than anyone realised, concentrated on a few services.
Because the response deadline is shorter than the filing deadline and runs from the request date, an unanswered request converts into a permanent denial faster than most other categories. These are worth prioritising above ordinary denial work.
Related codes
Terms used here — Appeal · Timely Filing · Minimum Necessary
How we handle it — Denial Management · AR Management · Practice Analytics
Primary sources
The rules behind CO-226, at the bodies that publish them.
- Evaluation and Management services guide (opens in a new tab)
Centers for Medicare & Medicaid Services — How E/M level is determined under the current medical decision making and time rules. The reference for any dispute about whether documentation supports a level.
- 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.
- Medicare claims appeals process (opens in a new tab)
Centers for Medicare & Medicaid Services — The five levels of appeal, what each requires and the deadline for each. Missing a level's deadline ends the appeal regardless of the claim's merits.
Looking for a different code? Search all 190 CARC and RARC codes
Questions about CO-226
Exactly what was requested, referencing the claim number and the request. Sending the full record by default frequently produces a further denial for supplying the wrong documents, which restarts the cycle with less time remaining.
Almost always routing rather than refusal. Requests arrive by post, portal, fax and electronic transaction, and where no one owns them across every channel, some sit unread until a denial surfaces them weeks later.
More urgent than most. The response deadline is shorter than the filing deadline and runs from the request date, so an unanswered request becomes a permanent denial faster than nearly any other category.
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