RARC MA83: Primary or Secondary Payer Not Indicated on the Claim
RARC MA83 means the claim did not indicate whether the billed payer is primary or secondary — a Medicare Secondary Payer (MSP) information gap. It rides with CO-16, and the fix is resubmitting with the correct payer-order information, including MSP type and any primary payment detail.
- Type
- Informational (supplemental)
- Usually paired with
- CO-16
- Fixable?
- Yes — always
- Typical fix
- Resubmit with correct payer order / MSP data
What does remark code MA83 mean?
Official X12 text: "Did not indicate whether we are the primary or secondary payer." The claim arrived without a clear answer to the first question every payer asks: whose bill is this first? On Medicare remits this is an MSP edit — the beneficiary has (or once had) other coverage on file, and your claim did not address it.
ERA mini-example: a 67-year-old still working with employer coverage comes in for a $310.00 procedure. Registration bills Medicare as primary out of habit; the claim returns CO-16 with MA83 because the MSP file shows an active group health plan. Billed correctly — employer plan first, Medicare secondary with the primary remit data — both payments post inside five weeks.
Which denial code does MA83 come with?
Almost always CO-16, since the claim is unprocessable until payer order is stated. Related codes tell nearby stories: MA04 (secondary claim missing primary payment data), CO-22 (care covered by another payer per COB), and N598 (another policy is primary). Match your pair in the denial code lookup.
How do you fix an MA83 denial?
- Interview the eligibility data, not the patient memory: run the MSP questionnaire and check the 271 response for other-payer segments.
- If another payer is primary, bill it first, then submit to Medicare as secondary with MSP type and full primary adjudication detail.
- If Medicare is genuinely primary, get the stale MSP record corrected through the BCRC, then resubmit indicating primary.
- Document the MSP determination in the patient record so the next claim does not repeat the loop.
How do you prevent MA83?
Make the MSP questionnaire a living document: complete it at intake for every Medicare patient and re-verify on a regular cycle (many practices align with the payer expectation of every 90 days for recurring services). Train front desk staff on the triggers — still working, working spouse, recent accident, workers comp claim — and route any "yes" to a payer-order determination before the visit bills. Accurate payer order at registration is the entire prevention story here.
Frequently asked questions
Federal MSP law makes Medicare secondary whenever certain other coverage exists: employer group health plans for working beneficiaries and working spouses, liability and no-fault insurance for accident claims, and workers compensation for job injuries. Paying primary when another payer owes first is an improper payment Medicare will recover — so it refuses to adjudicate claims that leave the question open.
Because the claim or the file said otherwise. A stale MSP record — an old employer plan, a closed auto claim — keeps flagging the beneficiary. Have the patient (or your office with the patient) contact the Benefits Coordination and Recovery Center to correct the MSP file, then resubmit indicating Medicare is primary.
The MSP type (working aged, disability, ESRD, liability, and so on), the primary payer identity, and the primary payment and adjustment detail in the COB loops — or a primary EOB on paper. If the primary denied, you carry the denial reason instead of payment data. Missing any leg of that tripod bounces the claim right back.
Sources & further reading
Reviewed by the ImmediCare Solutions RCM team
Certified billers and coders handling claims across 50+ specialties nationwide. This entry is reviewed against current payer policy and CMS rules. Last review: Jul 5, 2026.
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