CO 198 Denial Code: Authorization Exceeded

Official CARC description: “Precertification/notification/authorization/pre-treatment exceeded.” 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 198 actually means

An auth exists but this claim went past it — more visits, more units, or dates outside the window. The auth needs extending, or the excess needs clinical defense.

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.

Why CO 198 fires

How to fix CO 198

1

Step 1

Track auth utilisation live — request extensions BEFORE visits exhaust

2

Step 2

Ask for a retro-extension with progress notes showing continued necessity

3

Step 3

Date-window misses: sometimes just an auth-dates correction call

4

Step 4

Split billing: within-auth lines paid, excess lines appealed

How to appeal it

Appeal the excess with clinical progression documentation — payers grant retro-extensions when notes show necessity continued. Time-barred without notes, so document as you go.

Draft a CO 198 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 does denial code CO 198 mean?

Precertification/notification/authorization/pre-treatment exceeded. In practice: An auth exists but this claim went past it — more visits, more units, or dates outside the window. The auth needs extending, or the excess needs clinical defense.

Is CO 198 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 198 denial?

Appeal the excess with clinical progression documentation — payers grant retro-extensions when notes show necessity continued. Time-barred without notes, so document as you go.

Related denial codes