EOB denial code CO-45: what it means

What it means

The provider billed more than the insurer's contracted or allowed amount. For in-network care, the difference is written off and is not your responsibility.

Contractual Obligation — an adjustment the provider agreed to by contract. The patient is generally not billed for CO amounts.

Official X12 description

“Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement”

Typical cause

The billed charge is higher than the negotiated rate. With an in-network provider, this is a routine contractual write-off.

What to do next

1. 1If the provider is in-network, you should not be billed for this difference — it is a contractual adjustment.
2. 2If you are billed the difference (balance billing) by an in-network provider, that may not be allowed; contact your insurer.
3. 3If the provider is out-of-network, check whether No Surprises Act protections apply.