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M3 Remark Code: Same or Similar Equipment in Use

M3 means the payer denied the durable medical equipment because its records show the patient already has the same or similar equipment. The payer will not pay for two items that serve the same purpose for the same period.

Quick facts

Code
M3 (RARC M3)
Status
Active In use since January 1, 1997.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The supplier absorbs the denied amount because no valid advance notice shifted liability to the patient.
  • PR (Patient Responsibility): The patient is responsible, typically because the supplier obtained a valid advance beneficiary notice and billed with the GA modifier.
Official description
Equipment is the same or similar to equipment already being used.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What M3 means

M3 appears on durable medical equipment claims when the payer’s history shows the patient already has, or is currently renting, an item that does the same job. It is a Medicare DMEPOS remark at heart, though other payers use it. The paired reason code, usually CARC 96 or 50, carries the financial decision; M3 explains why.

“Similar” is broader than “identical.” A different model, a different supplier, or an upgraded version of the same kind of equipment can all trigger it.

Common causes

  • Another supplier is still billing a rental for a comparable item.
  • The patient received the item through a previous episode, hospital discharge, or a different payer.
  • A replacement was supplied without documentation of why the old item could not be used.
  • The patient switched suppliers mid-rental and the old rental was not closed out.
  • The item code was billed as a new item when it should have been a repair or accessory.

How to fix it

  1. Run a same or similar check through the payer or DME MAC and identify the item, supplier, and dates already on file.
  2. Confirm with the patient whether they still have and use the earlier equipment.
  3. If the earlier item was lost, stolen, damaged, or worn out, gather the supporting documentation (police or fire report, condition notes, prescriber order) and request reconsideration or resubmit with the payer’s required replacement indicator.
  4. If the patient’s medical needs changed, obtain updated clinical documentation supporting the different item.
  5. If none applies, post the denial. Bill the patient only if a signed advance notice covers the item.

How to prevent it

Make a same or similar inquiry part of intake for every new DME order, and record the result. When a check shows prior equipment, get an advance beneficiary notice before delivery or collect replacement documentation first. See eligibility and coordination of benefits denials for related front-end checks.

Codes that may appear with M3

  • CO-96 (Non-covered charge(s).): The item is treated as non-covered because a same or similar item is already on file.
  • CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Some payers frame the duplicate equipment as not medically necessary.
  • OA-18 (Exact duplicate claim/service (Use only with Group Code OA except where state workers' compensation regulations requires CO)): Used when the claim looks like an exact duplicate of equipment already billed, not just a similar item.
  • M86 (Service denied because payment already made for same/similar procedure within set time frame.): Payment was already made for the same or a similar procedure within a set time frame, a broader version of the same idea.
  • M94 (Information supplied does not support a break in therapy.): The information supplied does not support a break in therapy, so a new rental period will not start.
  • N171 (Payment for repair or replacement is not covered or has exceeded the purchase price.): Repair or replacement is not covered or has exceeded the purchase price.

M3 FAQ

How do I check whether a patient already has similar equipment?

Medicare DME suppliers can use the same or similar lookup available through their DME MAC's portal or eligibility tools. Other payers may provide equipment history on request.

Can equipment ever be replaced when M3 applies?

Yes, in some cases. Replacement may be covered when the item is lost, stolen, irreparably damaged, has reached its reasonable useful lifetime, or the patient's condition changed. You need documentation supporting the reason.

Can I bill the patient for an M3 denial?

Only if you obtained a valid advance beneficiary notice before delivery and the line came back as PR. Without it, the supplier generally absorbs the cost.