RemitBench/Denial codes/CO-198

CO-198 denial code

Code 198 is the better half of the authorisation pair. There was an approval. You went past what it covered, in visits, units or dates.

The code list's own wording: Precertification/notification/authorization/pre-treatment exceeded.

What it means: An approval is on file and this service falls outside its limits. More visits, more units, or a date past the authorised window.
Who owes the money: The practice, usually CO is the common pairing. Worth arguing rather than absorbing, because the payer has already accepted the treatment plan.
Is appealing worth it: Better odds than a 197. The payer authorised the care once, so the question is only about quantity, and clinical progress notes answer that directly.

You are in a stronger position than you think. The payer approved this treatment. It is now arguing about how much of it, which is a much narrower disagreement than whether the care was needed at all. Extension requests for authorisations that are already open succeed far more often than new requests after the fact.

Why the payer sent it

More visits or units were used than were authorised.
The authorised date range expired partway through a course of treatment.
The treatment took longer than expected and no extension was requested.
A second course of treatment was billed against the first authorisation.
Units were billed correctly and counted wrongly by the payer.

Remark codes you will see with it

Remark code	What it adds
N54	The claim information is inconsistent with the pre-certified or authorised services.
N362	The number of days or units exceeds the acceptable amount.
N640	Exceeds the number or frequency approved or allowed within the time period. See N640.

Remark code

What it adds

N54

The claim information is inconsistent with the pre-certified or authorised services.

N362

The number of days or units exceeds the acceptable amount.

N640

Exceeds the number or frequency approved or allowed within the time period. See N640.

Read the letters in front of the 198

CO-198: Contractual obligation. The usual pairing.
PR-198: Patient responsibility. Seen where the plan says the member accepted care beyond what was approved. Check the contract.
PI-198: Payer initiated. The patient owes nothing.

What to do next

Compare the authorisation against what you billed

Units, visits, dates. Find the exact point where the claim crossed the line, because that is what your extension request has to cover.
If the count is the payer's error: that is a reprocessing request with a number attached, and it moves quickly.
Request an extension with the progress notes

The strongest form of this argument is clinical progress: what has improved, what has not, and why more is needed. The payer already agreed the care was appropriate, so you are answering one question rather than three.
Build the tracking that prevents it

The whole cause is that nobody watched the count. A running total of authorised against used, visible to whoever books the next appointment, removes this denial entirely.

Codes that get mixed up with 198

Code	How it differs from 198
197	Authorisation absent rather than exceeded. A weaker position. See CO-197.
151	The information does not support this many services. A documentation judgment rather than an authorisation limit. See CO-151.
273	Coverage guidelines exceeded. A plan limit rather than an authorisation one. See CO-273.

Code 198 in dental

Most common on orthodontic cases and on managed care dental plans, where the authorisation covers a number of months or visits and a case that runs long crosses it.

Long cases need the extension before the limit, not after

An orthodontic case authorised for a set number of months will not warn you when it is close. Diarising the extension request a couple of months before the limit is the difference between a routine approval and an argument about care already delivered.

Questions people ask about CO-198

What is the difference between CO-197 and CO-198?

A 197 means the payer has no authorisation at all. A 198 means it has one and the service went beyond what it allowed. The second is a much better place to be, because the payer has already accepted that the treatment was appropriate and is only arguing about quantity.

Related codes

Back to all denial codes

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