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MA18 Remark Code: Claim Forwarded to Supplemental Insurer

MA18 is an informational alert. The claim information is also being forwarded to the patient's supplemental insurer, such as a Medigap plan, and any questions about supplemental benefits should be sent to that insurer.

Quick facts

Code
MA18 (RARC MA18)
Status
Active In use since January 1, 1997; last modified April 1, 2007.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • PR (Patient Responsibility): The deductible or coinsurance left after this payer's processing has been sent on to the supplemental insurer for consideration.
Official description
Alert: The claim information is also being forwarded to the patient's supplemental insurer. Send any questions regarding supplemental benefits to them.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What MA18 means

MA18 confirms a crossover. After processing the claim, the primary payer, typically Medicare, automatically sent the claim information to the patient’s supplemental insurer. The supplemental insurer will review what remains, usually deductible and coinsurance, under its own benefits.

This is good news for your workflow: you do not have to create a secondary claim for this balance.

What to do

  1. Post the primary payment and move the remaining balance to the supplemental insurer.
  2. Wait for the supplemental remittance before billing anyone else.
  3. Follow up after a reasonable period. If nothing arrives, confirm receipt with the supplemental insurer before submitting directly, to avoid a duplicate claim denial.
  4. Bill the patient only after the supplemental insurer has processed its share.

Codes that may appear with MA18

  • PR-1 (Deductible Amount): Deductible that the supplemental insurer will consider through the crossover.
  • PR-2 (Coinsurance Amount): Coinsurance forwarded to the supplemental insurer.
  • MA08 (Alert: Claim information was not forwarded because the supplemental coverage is not with a Medigap plan, or you do not participate in Medicare.): The claim was not forwarded because the coverage is not Medigap or you do not participate.
  • MA19 (Alert: Information was not sent to the Medigap insurer due to incorrect/invalid information you submitted concerning that insurer.): The claim was not forwarded because the Medigap insurer information was incorrect.
  • MA07 (Alert: The claim information has also been forwarded to Medicaid for review.): The claim was forwarded to Medicaid instead.

MA18 FAQ

Should I bill the supplemental insurer too?

Not immediately. Billing it directly while the crossover is processing can cause duplicate claims. Wait for its response, then follow up if nothing arrives.

Who do I ask about the supplemental payment?

The supplemental insurer. MA18 specifically directs questions about supplemental benefits to them rather than to the primary payer.

Can I bill the patient now?

Hold the balance until the supplemental insurer responds, since it may cover some or all of the patient's share.