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CO-B3 Denial Code (Deactivated): Covered Charges

CO-B3 reported covered charges on a claim. It was informational rather than a reason for an adjustment, and X12 deactivated it without naming a replacement.

X12 deactivated CARCB3 on October 16, 2003. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: CO-B3 (CARC B3)
Status: Deactivated StoppedOctober 16, 2003 (in use since January 1, 1995).
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: CO (Contractual Obligation): Informational; it did not assign any amount to the provider or patient.
Official description: Covered charges.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-B3 meant

CARC B3 carried the amount of charges the payer considered covered. It gave providers a quick view of how much of the bill fell within benefits, before cost-sharing and payment. It did not by itself reduce anything.

What replaced it

X12 did not name a replacement. Current 835 files show billed and paid amounts directly, and payers can report the allowed amount in an amount segment. The portions that are not covered are explained with adjustment codes such as CO-45 for contractual reductions, CO-96 for non-covered charges, and CO-78 for non-covered institutional days.

If you still see CO-B3

It only exists in old remittance data. Use it as a reference number when reconstructing historical payments, but do not post it as an adjustment. If a data conversion turned it into a ledger entry, reverse that entry so the account balance reflects only real payments and adjustments.

CO-45 (Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.): Explains the reduction from billed charges to the allowed amount.
CO-96 (Non-covered charge(s).): Non-covered charges, with a remark code explaining why.
CO-78 (Non-Covered days/Room charge adjustment.): Non-covered days or room charge adjustment on institutional claims.

CO-B3 FAQ

Where are covered or allowed amounts shown today?

The 835 carries claim and line amounts, and many payers report the allowed amount in a dedicated amount segment. Non-covered portions are explained with adjustment codes.

Should I post anything for CO-B3?

No. It was a reference figure. Post the payment and the actual adjustment codes on the claim.

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