What is CO 197?
The CO 197 denial code stands for “Precertification/authorization/notification is missing.”
In simple words — before doing certain medical procedures or services, the provider must get approval from the insurance company. If that approval isn’t received (or is wrong or expired), the claim will be denied with CO 197.
Example
A doctor performs an MRI scan, but the clinic didn’t get approval from the insurance before doing it.
When the claim is submitted, the insurance denies it with CO 197 – “Precertification/authorization/notification is missing.”
Common Reasons for CO 197 Denial
Here are some of the most frequent reasons behind CO 197 denial:
1) No prior authorization was obtained
What it means
The payer requires a prior approval before the service is performed, but nobody requested or obtained that approval.
Example
An outpatient clinic schedules an elective MRI. Staff never requested prior auth from the insurer. Claim submitted → denied CO 197.
Immediate actions to fix the denial
Confirm on the EOB that the denial reason is “authorization missing.”
Check your internal logs / authorization tracker first—sometimes the auth was requested but not recorded.
If no auth exists, call the payer’s authorization/medical review unit and ask whether retroactive (retro) authorization is possible. Document the representative’s name, time, and any confirmation.
If retro auth is allowed, obtain the auth number and resubmit the claim (or submit an appeal with the retro auth + supporting clinical documentation).
If retro auth is not allowed, prepare an appeal with clinical justification (emergency/urgent service notes may help) or discuss write-off / patient responsibility with your client.
Prevention controls
Maintain a preauthorization matrix (by payer + CPT/HCPCS) listing which services need auth.
Require schedulers / referral coordinators to verify auth status before booking.
Use an authorization tracking log with expiration dates and claim numbers mapped to auth numbers.
Add a pre-submission edit that blocks claim for auth-required CPTs if no auth number is present.
2) Authorization was obtained but expired before the service date
What it means
An authorization was issued but its effective dates do not include the actual date of service (DOS).
Example
Auth approved for 01-01 to 01-15. Procedure performed on 01-20. Claim submitted → denied CO 197 (auth expired).
Immediate actions to fix the denial
Retrieve the auth approval letter (or payer response) and verify the validity window.
Call the payer and ask if extension or retroactive date correction is permitted, especially if the delay was due to scheduling issues or administrative error.
If the payer permits extension/retro auth, get written confirmation or an auth number and resubmit.
If not permitted, assemble documentation explaining scheduling delay and appeal if there’s clinical justification (e.g., patient hospitalization delayed procedure).
Prevention controls
Track auth expiration dates in your authorization system and set alerts (e.g., 7–14 days before expiry).
When rescheduling a procedure, require staff to confirm the auth still covers the new DOS.
If auth window is short, schedule within the window or request extension proactively.
3) Wrong authorization number used
What it means
An authorization exists, but the number included on the claim is incorrect, mistyped, in the wrong claim field, or formatted incorrectly for that payer.
Example
Auth number is A1234567, but claim includes A123456 (one digit missing), or the number is placed in the wrong box/loop on electronic claim.
Immediate actions to fix the denial
Locate the original authorization document and verify the exact auth number and formatting.
Check the claim submission (paper/CMS-1500 Box 23 or electronic REF loop) to ensure the auth number was placed correctly.
Correct the claim (resubmit) with the exact auth number. If resubmission isn’t allowed, call payer to confirm whether they will accept a corrected claim or require an appeal.
Document the correction and the payer rep confirmation.
Prevention controls
Use copy-paste (not manual typing) from the auth letter into your claim field where possible.
Standardize where auth numbers are entered in your billing software and train staff on payer-specific field placement (e.g., REF with REF01 = “G1” for some DME Medicare contractors).
Implement a validation rule: if an auth number exists, the claim should not be batched without matching that auth to the DOS and CPT.
4) Authorization was for a different CPT or diagnosis
What it means
The payer granted an authorization, but it was for a different procedure code, a different diagnosis, or a different level of service than what was billed.
Example
Auth approved for CPT 70551 (MRI brain without contrast), but claim billed CPT 70552 (MRI brain with and without contrast). The billed CPT exceeds or differs from the auth → CO 197.
Immediate actions to fix the denial
Compare the approved CPT(s)/diagnosis in the auth letter with the billed CPT/ICD-10.
If the auth covers another, lower-level service, call the payer: can they expand/modify the auth to cover billed service (retro upgrade)?
If the billed service is medically necessary and differs, collect clinical documentation that justifies the more extensive service and submit an appeal with that documentation.
If the billed service was incorrect (coding error), correct and refile the claim with the CPT that matches the auth.
Prevention controls
When requesting auth, send the exact CPTs and diagnoses intended for the procedure—do not rely on vague descriptions.
Train clinicians and schedulers to match the clinical order to the exact CPT to be billed.
Require a pre-claim check that validates billed CPTs against existing auths and flags mismatches.
5) Provider performing the service was not covered under the authorization
What it means
The authorization was issued but limited to a specific provider, facility, or location. The actual billed provider or rendering clinician was not included, so the payer denies based on authorization mismatch.
Example
Auth granted for MRI at Facility A or by Dr. Smith, but the patient had the MRI at Facility B or with a different surgeon. Claim submitted by the actual provider → denied CO 197.
Immediate actions to fix the denial
Verify the provider/facility specified on the auth document.
If the auth covers a different provider/location, contact the payer to request an update or retro authorization for the rendering provider. Some payers allow correction if the change was due to provider availability or patient emergency.
If payer won’t retroactively expand auth, evaluate options: appeal with justification (e.g., sudden change due to emergent situation) or discuss patient responsibility/write-off per client instructions.
Prevention controls
When obtaining authorization, explicitly confirm the provider(s) and facility included on the auth.
For contracted networks, ensure that the rendering provider is in the approved provider list for that payer.
Build scheduler workflows that verify the facility/provider on the auth before service delivery and block scheduling unless aligned.
On-Call Scenario: CO 197 – Precertification/authorization/notification is missing.
Step 1: Identify the Denial
“May I get the denial date, please?”
Step 2: Check for Authorization in the System
Look in the billing system or EHR to verify if an authorization number (Auth#) is available.
Step 3: Based on System Check
If Authorization Number Is Available
Say:
“I have the authorization number. Could you please reprocess the claim using this Auth#?”
If the representative agrees:
Ask for the TAT (Turnaround Time) for reprocessing.
Record the Claim# and Call Reference#.
If the representative refuses or says the Auth# is invalid:
Ask:
“What is the time limit to send a corrected claim?”
Then collect the Claim# and Call Reference#.
If No Authorization Number Found
Check if services billed are Emergency or not
If YES:
“Could you please reprocess the claim, since this is an emergency service and does not require prior authorization?”
If the rep agrees → ask for TAT, Claim#, and Call Ref#.
If not → move to next step.
Step 4: Check for Related or Hospital Claims
Ask:
“Is there any hospital claim billed on the same date of service where an Auth# is present?”
Or:
“Do you have an Auth# on file for this patient on the same date?”
If Yes:
“Could you please use that Auth# and send the claim back for reprocessing?”
Then collect Claim# and Call Ref#.
If No:
Ask if retroactive authorization (Retro Auth) can be obtained:
“Is it possible to obtain a Retro Authorization# for this claim?”
Step 5: Retro Authorization Handling
If Retro Auth is possible:
“What is the procedure to obtain Retro Authorization?”
Then collect Claim# and Call Ref#.
If Retro Auth is not possible:
“What is the Fax number or mailing address to send an appeal?”
“How much is the time limit to send the appeal?”Then collect Claim# and Call Ref#.
Important Notes & Actions
Always follow your company or client’s specific process updates before taking any action.
If the authorization number (Auth#) is available and the insurance rep agrees to reprocess, note the TAT and set a follow-up accordingly.
If the Auth# is available but the rep asks for a corrected claim instead of reprocessing, update the Auth# in the system, use billing code “7”, and resubmit the corrected claim with the original claim number.
If the Auth# is missing but the service was an emergency, and the rep agrees to reprocess, record the TAT and follow up.
If the Auth# is not in the system but the rep finds it on their end or on the hospital claim, note the Auth# and request reprocessing; follow up per TAT.
If no Auth# is found and retro authorization is possible, follow the payer’s instructions to obtain it. Complete any required forms and attach clinical documents. If documents are missing, contact the client for assistance.
If retro authorization is not possible, the claim should be written off. However, if the client requests, send an appeal even after the time limit is crossed.
Check for authorization details on the Evicore portal for payers supported on the site. If access is available, verify if the Auth# is approved for the CPT code and service period.
Some payers may ask you to call Evicore directly to confirm or request authorization.
Click here for more AR Scenarios and Denials.