Skip to main content

M65 Remark Code: One Interpreting Physician per Claim

M65 means a claim that includes a purchased diagnostic test can only list one interpreting physician. If more than one physician interpreted tests, each must be billed on a separate claim.

Quick facts

Code
M65 (RARC M65)
Status
Active In use since January 1, 1997.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The claim or line is unpaid as submitted. Splitting it correctly is the path to payment; the patient is not billed.
Official description
One interpreting physician charge can be submitted per claim when a purchased diagnostic test is indicated. Please submit a separate claim for each interpreting physician.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What M65 means

When a billing provider buys the technical component of a diagnostic test from an outside supplier and bills for it, the claim reports purchased-service details. Medicare’s rules for these claims allow only one interpreting physician per claim. M65 says your claim listed more than one, so it must be split and resubmitted.

This is a Medicare-rooted remark for professional claims with purchased diagnostic tests.

Common causes

  • Several tests interpreted by different physicians were billed together on one claim.
  • The billing system grouped all same-day services for the patient onto a single claim.
  • A covering physician read one of the studies and was added as a separate rendering provider.

How to fix it

  1. Identify each interpreting physician on the original claim.
  2. Create a separate claim for each, with the correct rendering provider (box 24J) and the purchased-service information (box 20 or the electronic equivalent).
  3. Submit the new claims. If the original was partly processed, void or correct it first so nothing duplicates.
  4. Confirm each claim carries only the tests that physician interpreted.

How to prevent it

Set a claim-splitting rule in your billing system for purchased diagnostic tests so claims break by interpreting physician automatically. Watch for duplicates when you split; see duplicate claim denials.

Codes that may appear with M65

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim structure contains billing errors.
  • CO-A1 (Claim/Service denied.): The claim was denied at claim level because of the multiple interpreters.
  • M12 (Diagnostic tests performed by a physician must indicate whether purchased services are included on the claim.): The claim did not say whether purchased services were included.
  • M133 (Claim did not identify who performed the purchased diagnostic test or the amount you were charged for the test.): The claim did not identify who performed the purchased test or what was charged.
  • N149 (Rebill all applicable services on a single claim.): The opposite instruction: rebill all applicable services on a single claim.

M65 FAQ

Why does the payer limit interpreters per claim?

Purchased test claims report a single purchased service provider and pricing detail at claim level. Mixing interpreters makes it unclear which details apply to which test.

How do I split the claim?

Create one claim per interpreting physician, each with its own rendering provider in box 24J and its own purchased-test details.

Does M65 apply to tests that were not purchased?

M65 is specific to claims indicating a purchased diagnostic test. Other claims follow the usual rules for multiple rendering providers.