Authorization does not apply to the billed services
The authorization number is valid, but it was issued for a different service, code, site or date than the one on the claim.
CO = Contractual Obligation. The provider owes the difference. The patient cannot be billed for this amount. The same reason code can appear with a different group code; the group decides who may be billed.
Usual causes
- Procedure changed during surgery (a different or additional CPT code).
- Authorization for one site of care, service performed at another.
- Authorization for a different date range.
The fix
Compare the claim with the authorization. If the claim was coded wrong, correct it. If the service really changed, call the payer: many will update the authorization within a few days when the change was clinically necessary. Then resubmit. Appeal with the operative note when they refuse.
Appeal or corrected claim?
Corrected claim when the coding is wrong; authorization update then resubmission when the service changed; appeal with clinical notes as a last step.
Deadline to watch
Authorization update windows are short (days). Timely filing and appeal windows still apply.
Exact limits are in your payer contract or provider manual. When in doubt, send the correction or appeal this week.
CO-284 in short
What does CO-284 mean?
The authorization number is valid, but it was issued for a different service, code, site or date than the one on the claim. The official X12 text reads: "Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the billed services."
What usually causes a CO-284 denial?
Procedure changed during surgery (a different or additional CPT code). Authorization for one site of care, service performed at another. Authorization for a different date range.
How do I fix CO-284?
Compare the claim with the authorization. If the claim was coded wrong, correct it. If the service really changed, call the payer: many will update the authorization within a few days when the change was clinically necessary. Then resubmit. Appeal with the operative note when they refuse.
Should I appeal CO-284 or send a corrected claim?
Correct or appeal (see note). Corrected claim when the coding is wrong; authorization update then resubmission when the service changed; appeal with clinical notes as a last step.
What deadline applies to CO-284?
Authorization update windows are short (days). Timely filing and appeal windows still apply.