CO-13: date of death precedes the date of service.

What X12 says CARC 13 means

The date of death precedes the date of service.

CARC 13 · Start 01/01/1995.

In plain terms: The patient's date of death is earlier than the date of service.

What it means on a remittance

The payer’s file shows a date of death that is earlier than the date of service on the claim. CARC 14 is the matching code for a date of birth that follows the date of service. Both are date-logic edits that usually point to a data error on one side.

Typical causes

• The date of service was keyed wrongly, for example the wrong year.
• The payer’s file has an incorrect date of death.
• The claim was billed under the wrong member, such as a family member with the same name.
• The payer’s date of death came from a report that was wrong or was later corrected.

These are common billing patterns, not a diagnosis of your claim. The remittance and the payer's policy decide.

What to check

1. Compare the date of service on the claim with the chart and schedule.
2. Confirm the patient and subscriber identifiers on the claim.
3. Ask the payer what date of death it holds and what source it used.
4. Check whether any part of the service legitimately occurred before the death.

Correct, resubmit or appeal

If the date of service was wrong, correct it and resubmit. If the payer’s date of death is wrong, ask the payer how to get its file corrected and request reprocessing. Do not bill for services that were not furnished.

Medicare dates that apply

A Medicare redetermination request must be filed within 120 calendar days from the date a party receives the notice of the initial determination; receipt is presumed 5 calendar days after the notice date unless there is evidence to the contrary (42 CFR 405.942(a)), and a late request can be considered for good cause (405.942(b)). Other payers set their own appeal windows in the contract or plan documents, so read the notice for the date. The tool above runs the date math.

Related codes

X12 does not publish a table that pairs each code with remark codes; the payer picks the remark code and prints it beside the CARC on the same remittance line.

Other codes: CARC 14 (date of birth after service), CARC 26 (expenses before coverage) and the full lookup.

Worked example (hypothetical)

A claim denies with CO-13. The date of service was keyed as 2025 instead of 2026, and the payer’s file shows a date of death in late 2025. The biller corrects the year and resubmits.

Sources

• X12: Claim Adjustment Reason Codes — code text, usage notes and dates (list dated 10/30/2026, retrieved 2026-11-02)
• 42 CFR 405.942 — eCFR, current through 2026-10-29 (retrieved 2026-11-02)

Code descriptions are X12 copyrighted material, quoted here only for the codes on this page and linked to the owner. For the full lists, use X12. The X12 text and the Medicare rule above were read from these pages on November 2, 2026. Causes, checks and examples are general billing practice written for this page, not X12 content. Payers revise code lists, contracts and policies, so confirm anything that affects a claim or a deadline with the payer.