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CO-D19 Denial Code (Deactivated): Operative Report Missing

CO-D19 meant the claim lacked a physician or operative report or other supporting documentation. X12 deactivated it and its notes direct payers to CARC 16 with the appropriate remark code, such as M29.

X12 deactivated CARCD19 on June 30, 2007. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: CO-D19 (CARC D19)
Status: Deactivated StoppedJune 30, 2007 (in use since January 1, 1995).
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: CO (Contractual Obligation): Providing documentation was the provider's responsibility; the patient was not billed.
Official description: Claim/Service lacks Physician/Operative or other supporting documentation
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-D19 meant

CARC D19 was mostly seen on surgical claims. The payer needed the physician’s operative report, or some other supporting record, to process the service, and it was not received. The claim was denied until the documentation arrived.

What replaced it

X12’s note says to use code 16 with an appropriate remark code. The current combination is usually CO-16 with remark M29 for a missing operative note, or N233 if one was sent but was incomplete. Many payers also use CO-252 to request an attachment.

If you still see CO-D19

It is limited to older claims. For the same problem now, obtain the signed operative report from the surgeon or facility, send it through the payer’s attachment process referencing the claim, and follow up to confirm receipt. For procedures that routinely trigger requests, consider attaching the report with the initial claim.

CO-16 (Claim/service lacks information or has submission/billing error(s).): Named replacement: claim lacks information, explained by a remark code.
M29 (Missing operative note/report.): Remark code for a missing operative note or report.
N233 (Incomplete/invalid operative note/report.): Remark code for an incomplete or invalid operative note or report.
CO-252 (An attachment/other documentation is required to adjudicate this claim/service.): An attachment or other documentation is required to adjudicate the claim.

CO-D19 FAQ

When do payers ask for the operative report?

Often for unlisted procedures, claims with modifiers that increase payment, unusual combinations of procedures, or services that are subject to review.

What should accompany the report?

The claim number or attachment control number, and any other records the payer lists, such as a pathology report or implant log.

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