CO-197 means the payer required a precertification or authorization for the service, and none was on file. It’s one of the most common denials for therapy, behavioral health, imaging and procedures, and one of the most frustrating, because the care has already been delivered.
Step 1: confirm whether an authorization existed
Before anything else, check the payer portal and your records. Often an authorization was obtained, but:
- the auth number wasn’t on the claim (this can also show up as CO-15),
- it was issued under a different provider or location,
- the dates didn’t cover the date of service, or
- it was for a different code than the one billed.
If the auth was valid, add or correct it and submit a corrected claim. That’s the quickest fix.
Step 2: if there was no auth, ask about a retro authorization
Some payers allow retroactive authorization within a short window, especially if coverage couldn’t be verified at the time or the service was urgent. Call the payer, explain the situation, and ask whether a retro auth is possible. If it is granted, resubmit with the new number.
Step 3: appeal if the payer allows it
If retro auth isn’t available, check whether the payer accepts appeals for authorization denials. A strong appeal includes clinical notes showing medical necessity and any proof that you tried to obtain the auth or that the patient’s coverage information was wrong at the time.
Watch the deadline. Appeals have time limits, often 60 to 180 days from the denial. An unworked CO-197 eventually becomes a permanent write-off.
CO-198 is the close cousin
CO-198 means an authorization existed, but the services went past it: more visits or units than approved, or dates outside the auth period. The fix is the same mindset: request an extension or a new auth, then appeal or resubmit.
How to stop CO-197 from coming back
- Check auth requirements during eligibility, before the first visit, for every payer.
- Track approved visits and end dates per patient, and flag patients a few visits before the limit.
- Request extensions early, before the auth runs out, not after the denial arrives.
- Put the auth number on every claim where the payer requires it.
For mental health and physical therapy practices, an authorization tracker is usually the single biggest denial reduction available.
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