EOB denial code CO-204: what it means

What it means

This specific service, equipment, or drug is not a benefit under your current plan.

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

Official X12 description

“This service/equipment/drug is not covered under the patient's current benefit plan”

Typical cause

The item falls outside your plan's covered benefits, or a different plan tier would cover it.

What to do next

1. 1Check your plan's covered-benefits list and formulary (for drugs).
2. 2Ask whether a covered alternative exists.
3. 3If you believe it should be covered, file an internal appeal; for drugs, ask about a formulary exception.