Denial code · group CO
CO-198: The service went beyond the units, visits or dates the authorization allowed
Short answer
CO-198 means an authorization was on file but the claim went past it: more units or visits than approved, a date of service after the approval ended, or a code billed more often than the approval allowed. The payer pays up to the approved amount and denies the remainder. The fix is a request for additional units or an extension followed by a corrected claim, or an appeal when the payer's unit count is wrong.
Look up other codes in the denial code library.
Last reviewed by the Remitwright billing team. Editorial policy
Group CO means contractual obligation: the balance is written off, not billed to the patient. The number is the reason; the two-letter group says who carries the balance.
Remark codes that usually come with CO-198
- N54
- What was billed does not match what was precertified or authorized
- M62
- The treatment authorization code on the claim is missing, incomplete or not valid
Common causes
The visits ran out before the renewal was approved
An approval for a set number of therapy visits is used up and the patient keeps coming while the renewal request sits in the payer's queue. Every visit after the last approved one denies, even if the renewal is later granted from the date of the request.
The date of service is after the approval ended
Approvals carry an end date. Home care, ABA and DME rentals are billed in cycles, and a cycle that crosses the end date splits: days inside pay, days outside deny CO-198.
Units per day or per week exceed the approval
The approval sets a daily or weekly cap, and the schedule did not follow it. Two technicians drawing from one approval, a double session on one day, or 15-minute units counted differently from the payer's count all push a line over.
The payer counts units differently from the practice
The practice counts sessions; the payer counts 15-minute units, or the reverse. A claim can be inside the practice's count and over the payer's. The payer's portal counter is the one the edit uses.
Two approvals overlap and the payer applied the wrong one
A renewed approval that starts before the old one ends, or a second approval for a related service, can be applied against the wrong lines. The units look exhausted when they are not.
How to fix it and resubmit
- 1
Reconcile units against the payer's counter first
Pull the approval letter and the payer portal's remaining-units figure, then list the claims billed against it with units per line. You need to know whether the payer or the practice has the count wrong before choosing a route.
- 2
Appeal when the payer's count is wrong
If claims from another provider were counted against your approval, units were double-counted, or the wrong approval was applied, appeal with the approval letter and a unit ledger showing each date and the units billed. Ask for reprocessing of the denied lines.
- 3
Request additional units or an extension when the count is right
Submit a request for more units or a later end date with the clinical justification. Some payers backdate to the day the units ran out; many approve only from the request date. Resubmit the denied lines as a corrected claim once the approval is updated.
- 4
Write off what the payer will not extend
Units the payer refuses to add are a contractual adjustment under the CO group. Billing the patient for them is only possible where the plan allows it and the patient signed a notice before the extra services. Record the reason so the pattern is visible.
How to prevent it
- An authorization tracker in the practice management system that shows units remaining per patient per payer, reduced at charge entry, with an alert well before the units run out
- Renewal requests started early enough to clear the payer's review time before the approval ends, with the lead time set per payer
- Daily and weekly caps from the approval written into the scheduling template so the schedule cannot exceed them
- One owner for each authorization when several clinicians draw from the same approval
A CO-198 on therapy visits past the approval
A physical therapy clinic holds an approval for twelve visits. The patient attends fourteen before the renewal is approved. Visits thirteen and fourteen return CO-198 with N54. The clinic asks the payer to backdate the renewal; the payer approves it from the date of the request, which is after both visits. The two visits are written off. The clinic moves its renewal trigger to the ninth visit and adds a remaining-visits alert to the schedule. This is a hypothetical example.
Official text: the X12 claim adjustment reason code list. The meaning above is our paraphrase for billers; the list is the authority.
FAQ
Questions about CO-198
Does the payer pay anything on a CO-198 claim?
Can I bill the patient for the visits over the authorization?
How do I know how many units are left?
Can a CO-198 be appealed?
What is the difference between CO-198 and CO-151?
Next step
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While you wait: see the sample weekly report or read how to work claim denials. You can also download the sample weekly report (PDF).