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M86 Remark Code: Same or Similar Service Already Paid

M86 means the service was denied because the payer already paid for the same or a similar procedure within a defined time frame. It is a frequency or interval limit, not always a duplicate claim.

Quick facts

Code
M86 (RARC M86)
Status
Active In use since January 1, 1997; last modified June 30, 2003.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The denied service is a provider write-off under the frequency rule, unless the patient agreed in advance to pay.
  • PR (Patient Responsibility): The payer holds the patient responsible, typically when a valid advance notice of non-coverage was on file.
Official description
Service denied because payment already made for same/similar procedure within set time frame.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What M86 means

Many services have interval rules: the payer will pay once per day, once per year, or once within another fixed window. When a claim arrives for a service that matches, or is similar to, one already paid within that window, the payer denies it and reports M86. The earlier payment can be to your practice or to another provider entirely.

The words same or similar matter. The payer may treat two different codes as similar for frequency purposes, especially when one is a more limited version of the other or they are alternatives for the same clinical goal.

Common causes

  • The same service repeated before the payer’s interval has passed.
  • Another provider performed a similar service earlier in the window.
  • A corrected claim submitted as a new claim instead of a replacement, so the payer sees the service twice.
  • Date-of-service errors that pull two services into the same window.
  • Medically justified repeats billed without a diagnosis or modifier that shows why.

How to fix it

  1. Confirm the earlier paid service and its date. Check your own history first, then ask the payer.
  2. If it is your own duplicate, stop. If you meant to correct the first claim, submit a replacement with frequency code 7 rather than a new original claim.
  3. If the dates or codes were wrong, correct them and resubmit.
  4. If the repeat was necessary, gather documentation showing the change in condition or other reason and appeal, citing any policy exceptions.
  5. If the denial is correct, write it off, or bill the patient only when an advance notice supports it.

How to prevent it

  • Check service history or eligibility responses for frequency-limited services before scheduling.
  • Use advance notices when a service may exceed frequency limits.
  • Review duplicate claim prevention to keep resubmissions from looking like repeats.

Codes that may appear with M86

  • PR-119 (Benefit maximum for this time period or occurrence has been reached.): The benefit maximum for the time period has been reached.
  • OA-18 (Exact duplicate claim/service (Use only with Group Code OA except where state workers' compensation regulations requires CO)): An exact duplicate claim or service, when the prior payment was for the identical line.
  • CO-151 (Payment adjusted because the payer deems the information submitted does not support this many/frequency of services.): The payer deems the frequency of services not supported by the information submitted.
  • M90 (Not covered more than once in a 12 month period.): A specific 12-month frequency limit.
  • N640 (Exceeds number/frequency approved/allowed within time period.): Exceeds the number or frequency allowed within a time period.
  • N117 (This service is paid only once in a patient's lifetime.): A once-in-a-lifetime limit.
  • M80 (Not covered when performed during the same session/date as a previously processed service for the patient.): A same-session conflict with a previously processed service, rather than a time-window frequency limit.

M86 FAQ

Is M86 the same as a duplicate claim denial?

Not exactly. A duplicate denial means you billed the same thing twice. M86 can apply when a different but similar service, possibly from another provider, was paid within the payer's time window.

How do I find out who was paid earlier?

Ask the payer, or check the patient's eligibility and history responses where available. Some payers share the date of the earlier service on request.

Can M86 be overturned?

Yes, if the earlier service was different, the time window has actually passed, or a documented clinical change justifies the repeat under the payer's policy.