CO 226 Denial Code: Provider Info Not Received

Official CARC description: “Information requested from the Billing/Rendering Provider was not provided or was insufficient/incomplete.” Here’s what it actually means, why it fires, and how to get the claim paid.

Contractual Obligation (CO)Fix steps belowFree appeal letter draftNo PHI needed

What CO 226 actually means

The payer asked YOUR office for something — records, a W-9, credentialing data — and either got nothing or not enough. Often the request letter went to an old address or sat in an unworked queue.

Liability group: CO = Contractual Obligation — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.

Also written: CO-226, CO226, “denial code 226”, “226 denial code” or “reason code 226” — same CARC, different ERA formatting.

Why CO 226 fires

How to fix CO 226

1

Step 1

Find the original request — call the payer for the exact list and deadline if lost

2

Step 2

Send everything on the list in one package, indexed, claim number on each page

3

Step 3

Update the correspondence address on the payer file

4

Step 4

Request reopening rather than fresh appeal when documents were merely late

Appeal it — or fix and resubmit?

Submit the requested information with a reopening/reconsideration request. If you can show the response WAS sent timely (fax confirmation, portal receipt), demand reprocessing without penalty.

Draft a CO 226 appeal letter now ↓

Draft the appeal letter

Fill in the denial facts — use placeholders, never real patient data (the letter keeps [PATIENT NAME]-style fields so you can merge real details privately). A payer-ready draft with an enclosure checklist comes back in ~20 seconds.

Your appeal letter draft will appear here.

Frequently asked questions

What is the CO 226 denial code description?

The official CARC description for CO 226 is: “Information requested from the Billing/Rendering Provider was not provided or was insufficient/incomplete.” In practice: The payer asked YOUR office for something — records, a W-9, credentialing data — and either got nothing or not enough. Often the request letter went to an old address or sat in an unworked queue.

What does denial code 226 mean on an EOB?

Denial code 226 under the CO group (Contractual Obligation) means: Information requested from the Billing/Rendering Provider was not provided or was insufficient/incomplete. The number is the reason; the CO prefix decides who is liable — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.

Is CO-226 the same as CO226 or “denial code 226”?

Yes. CO 226, CO-226, CO226 and “denial code 226” are the same CARC — clearinghouses, payer portals and PM systems just print it differently. Only the group prefix (CO, PR, OA or PI) changes the meaning, because it changes who has to absorb the amount.

Is CO 226 the provider’s write-off or the patient’s responsibility?

CO stands for Contractual Obligation — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.

Can you appeal a CO 226 denial?

Submit the requested information with a reopening/reconsideration request. If you can show the response WAS sent timely (fax confirmation, portal receipt), demand reprocessing without penalty.

Related denial codes