CO-197 Denial Code: Precertification / Authorization Absent

What Does CO-197 Mean?

CO-197 means the service required prior authorization and the payer has no record of one — or the authorization on file doesn't match what was billed. These are among the most expensive denials in medicine because they concentrate on exactly the services payers gate: surgery, advanced imaging, infusions, and inpatient stays.

Code group: CO (Contractual Obligation) · Appealable: Highly workable: linkage failures and mismatches are recoverable, retro-auth covers urgent care, and merits appeals succeed more often than practices expect. Pure process failures on elective services are the hard losses.

Why CO-197 Happens

No authorization was obtained — the scheduling team didn't know the payer required one, or the requirement was added recently and nobody caught the policy change.
The auth exists but doesn't match the claim: different CPT code than approved, different site of service, different provider, or more units than authorized.
The authorization expired before the date of service — common with rescheduled surgeries and long infusion courses.
Urgent or emergent care was delivered without time to authorize, and the claim went out without the retro-authorization the payer's policy allows.
The auth was obtained and is in the payer's own system — but their claims platform didn't link it. It happens more than payers admit.

How to Fix a CO-197 Denial — Step by Step

Search your records and the payer portal for any authorization: if one exists, get the auth number, verify what it covers, and request claim reprocessing with the auth attached — a linkage failure is a phone call, not a loss.

If the auth mismatches the claim (code, site, units), determine which is right. If the claim is right, request an auth amendment or file an appeal explaining the clinical variance — intraoperative changes are appealable with the op note.

For urgent/emergent services, file for retroactive authorization immediately — most payers allow it within a tight window (often 24–72 hours, sometimes 14 days) for genuine urgency.

If no auth exists and no exception applies, appeal on the merits anyway when the service was clearly medically necessary — some payers reduce rather than deny on first-level review, and state rules increasingly limit auth-based nonpayment for necessary care.

Either way: add the service and payer to your auth-required grid so it never recurs.

CO-197 Appeal Letter Template

Adapt this wording to your claim — replace the bracketed fields and attach the documentation it references:

Claim [number] denied CO-197. [Option A:] Authorization [#] was issued on [date] covering [CPT/site/units]; the claim matches the authorization, and we request reprocessing with the authorization linked. [Option B:] The service was urgent — delay would have jeopardized the patient per the attached documentation — and we request retroactive authorization per your policy [reference] and reprocessing.

How to Prevent CO-197

Maintain a payer-by-payer auth grid for your top 50 services, reviewed quarterly — auth lists change constantly.
Match auth to claim before submission: CPT, site, provider, units, and date range.
Track auth expiration dates against the surgery schedule; rescheduling is the silent auth killer.

Related Denial Codes

CO-50 — Not medically necessary CO-96 — Non-covered

← Back to the full denial code library

Reviewed by the LegitMedBilling denial management team. This guide is general billing information, not legal or payer-specific advice — always verify against your payer contract and current policy.

Frequently Asked Questions

Can we get an authorization after the service was performed?

Often, yes — retroactive authorization exists for urgent and emergent care at nearly every payer, with windows from 24 hours to 14 days. Some payers also grant retro-auths for administrative failures if you can show the service would have been approved. File fast; the windows are unforgiving.

The payer approved the surgery but we did an additional procedure during the case. Now what?

Appeal with the operative note. Intraoperative findings that expand the procedure are a recognized appeal basis — the surgeon couldn't have known preoperatively, and payers' own policies typically address unlisted intraoperative variance. The unauthorized add-on is winnable; going silent on it is not.

Can the patient be billed for a CO-197 denial?

Generally no — obtaining authorization is the provider's contractual responsibility for in-network care, and CO-prefix liability sits with the provider. Balance-billing patients for your auth process failure violates most contracts and several state laws.

How do we keep up with payers changing auth requirements?

Assign ownership: one person or your billing partner reviews payer bulletins and updates the auth grid quarterly, and every scheduled service gets an auth check at booking. Practices that treat auth requirements as static are the ones funding payers' denial statistics.