CO-284CO group · Authorization

CO-284 denial code: precertification valid, but not for these services

CO-284 is the denial that arrives when the operating room finds something the authorization did not anticipate.

CO-284 fires where a valid authorization is on file but the services billed fall outside what it approved. Intraoperative findings, converted approaches and added components are the recurring causes.

What CO-284 means

Authorizations are granted for named services, and clinical reality does not always match the plan. A procedure converted from one approach to another, an additional component found necessary once the case began, or a staged plan compressed into one session all produce services the authorization does not name. The appeal is a clinical narrative: what was found, when the decision was made, and why deferring to a second authorized encounter would have been worse for the patient.

Why CO-284 fires

  • Intraoperative findings changed the procedure performed.
  • An additional component was necessary and was not separately authorized.
  • The approach converted and the billed code changed with it.
  • The authorization named a different site, provider or date.

Is CO-284 worth appealing?

Sometimes worth appealing

Argue the clinical decision. Where the change was made in theatre on findings, the operative note carries the appeal — describe the finding, the decision and why a separate authorized encounter was not the safer course.

How to resolve or appeal CO-284

  1. 1

    Compare authorized against performed

    Line by line, so the appeal addresses the actual gap rather than the procedure generally.

  2. 2

    Lead with the operative note

    The finding and the decision point, quoted, are what a reviewer credits.

  3. 3

    Address the alternative

    Say why staging into a second authorized session would have exposed the patient to unnecessary risk.

CO-284 — frequently asked

Should authorization have been sought during the case?
That is rarely practicable, and payers understand it. What the appeal has to establish is that the decision was clinically driven and documented at the time, not reconstructed afterwards.
Does this affect the authorized portion?
It should not. Where part of the claim was authorized and part was not, the authorized services should still pay, and a denial of the whole claim is worth challenging on that basis alone.

Related guides

CO-198 · AuthorizationCO-296 · AuthorizationCO-197 · Authorization

Sources

Reason-code meanings are paraphrased from the X12 Claim Adjustment Reason Code list for plain-language reference; they are not reproduced verbatim. This is general information, not legal, coding, or medical advice — always confirm against the payer's remittance and policy.

Turn this CO-284 denial into a signed appeal

Upload the denied EOB and Merits builds a complete CO-284 appeal — the argument, the payer's own coverage criteria, and your federal appeal rights, every claim cited to a named source. $9 a letter. No account.

Appeal a denial →