Authorization number
An authorization number is the reference a payer issues when it approves a prior authorization — the identifier that ties the approval to the claim for the service it covers.
Updated
An authorization number (sometimes called an auth number, certification number, or reference number) is the identifier a payer returns when it approves a request for a service that requires prior authorization. It is the evidence that the approval exists and the key that links it to the claim later submitted for the authorized service.
An approval is usually scoped, not open-ended: it typically applies to a specific service or set of services, an approved number of units or visits, and a date range. The claim has to fall within that scope, and the authorization number is what lets the payer match the two.
In practice
Recording the authorization number is not enough on its own; the claim also has to match the approval it points to. A claim billed for more units than were approved, outside the approved date range, or for a different service can be denied even though a valid authorization exists — the approval and the claim have to agree. How and where the number is reported on a claim is set by each payer's billing instructions.
Commonly confused with
- Claim number: A claim number identifies a submitted claim in the payer's system; an authorization number identifies the advance approval the claim relies on.
- Referral: A referral directs a patient to another provider; an authorization number records a payer's approval of a specific service.