Secondary claim
A secondary claim bills the next plan after the primary has paid — and it must carry what the primary did, or it cannot be adjudicated.
Updated
A secondary claim is a claim submitted to a patient's next plan after the primary payer has adjudicated. It is not a resubmission of the original: the secondary payer needs to know what the primary allowed, paid, and left outstanding before it can decide what it owes.
That information travels with the claim as the primary's remittance detail. A secondary claim sent without it is a claim the payer cannot process, which is why secondary billing depends on the primary's remittance having been posted accurately first.
In practice
Secondary billing is where posting quality stops being an internal matter. If the primary's payment, adjustments, and patient responsibility were posted as a lump sum rather than line by line, the detail the secondary payer requires no longer exists in a usable form — and the balance either goes unbilled or gets billed to the patient in error.
The order is set by coordination of benefits rules, not by preference, and the secondary plan's payment is based on what remains after the primary — which can be a fraction of what the service drew as primary, or nothing at all.
Commonly confused with
- Coordination of benefits: COB is the rule set that decides which plan is primary. A secondary claim is what you send once that order is known.
- Corrected claim: A corrected claim replaces a claim with the same payer. A secondary claim is a first submission to a different payer.