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CO-D2 Denial Code (Deactivated): Drug Name/Strength/Dose

CO-D2 meant the claim did not include the name, strength, or dosage of the drug furnished. X12 deactivated it and directs payers to CARC 16 with remark codes as needed, such as M123.

X12 deactivated CARCD2 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-D2 (CARC D2)
Status: Deactivated StoppedOctober 16, 2003 (in use since January 1, 1995).
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: CO (Contractual Obligation): The provider needed to supply the drug details; no amount moved to the patient.
Official description: Claim lacks the name, strength, or dosage of the drug furnished.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-D2 meant

CARC D2 applied to claims for drugs given or supplied by a provider. The payer needed to know which drug, in what strength, and at what dose to price and review the line. When that description was missing, the claim was denied as incomplete.

This often came up with drug codes that cover many products, where the procedure code alone does not identify what was given.

What replaced it

The note on D2 says to use code 16 with remark codes. Current remittances show CO-16 with remark M123, which names the missing drug name, strength, or dosage. If the dose was reported but the payer believes it is too high, the code is CO-153 instead.

If you still see CO-D2

You will find it only in older data. For a missing drug detail today, check the claim for the NDC, unit of measure, and quantity, plus any narrative the payer requires for unlisted or not-otherwise-classified drug codes. Add what is missing and resubmit a corrected claim.

CO-16 (Claim/service lacks information or has submission/billing error(s).): Named replacement: claim lacks information, used with a remark code.
M123 (Missing/incomplete/invalid name, strength, or dosage of the drug furnished.): Remark code for a missing, incomplete, or invalid drug name, strength, or dosage.
CO-153 (Payer deems the information submitted does not support this dosage.): Used when the dosage is reported but not supported by the information submitted.

CO-D2 FAQ

Where do drug details go on a claim?

Payers commonly require the National Drug Code and quantity in the claim's drug identification fields, and some also want the drug name and strength in the line narrative, especially for unlisted drug codes.

Is CO-D2 about the drug being non-covered?

No. It was a missing-information denial. Once the details were supplied, the claim could be processed normally.

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