Arkansas Medicaid Denial Reason Code List and Appeals

Arkansas Medicaid denial codes are the standardized messages printed on your Remittance Advice that explain why a claim was not paid. Each code points to a specific problem: the patient wasn’t eligible on the date of service, another insurer should have paid first, a required field was missing, prior authorization was never obtained, or the service itself isn’t covered. Decoding the message correctly is what tells you whether to correct and resubmit, request reconsideration, or write the charge off.

Where to Find the Codes on Your Remittance Advice

Every processed claim generates a Remittance Advice (RA) showing whether Arkansas Medicaid paid, reduced, or denied it. Denials are explained with two nationally standardized code sets: Claim Adjustment Reason Codes (CARC), which explain the financial adjustment, and Remittance Advice Remark Codes (RARC), which add context about what went wrong or what to do next.¹ Both appear at the claim line level, so you can see which service triggered the problem.

Arkansas Medicaid also uses internal Explanation of Benefit (EOB) codes that generally map back to the national CARC and RARC standards. When an EOB code is unfamiliar, cross-referencing the corresponding CARC or RARC usually clarifies the issue. You can also look up claim status through the Arkansas Medicaid provider portal at portal.mmis.arkansas.gov.

Eligibility Denials

Eligibility denials mean the patient’s coverage status didn’t line up with the date of service. These are among the most common denials and usually the easiest to prevent with a verification check before the appointment.

CARC 13: The patient’s date of death precedes the date of service.¹
CARC 140: The patient’s health identification number and name don’t match what’s on file.¹
RARC N129: The patient isn’t eligible because of age. This frequently appears with ARKids First claims when a child ages out of the program.²

Verify the patient’s Medicaid ID, name spelling, and coverage dates through the provider portal before resubmitting. CARC 140 is often a transposed digit or a misspelled name. If the patient received retroactive eligibility after the service date, the claim is still subject to the standard 12-month filing deadline from the date of service with no exceptions.³

Third Party Liability Denials

Arkansas Medicaid is the payer of last resort. If the patient has private insurance, Medicare, or any other coverage, that source must pay first.⁴

CARC 22 is the standard code, indicating the service may be covered by another payer under coordination of benefits.¹ When this appears, bill the primary insurer first, then submit to Arkansas Medicaid with the primary payer’s Explanation of Benefits attached. Medicaid pays the difference between what the primary insurer paid and the Medicaid-allowed amount, but only if the primary payment was less than the Medicaid rate. If the primary payer met or exceeded the Medicaid allowed amount, Medicaid owes nothing.⁴

Submission and Formatting Errors

These denials have nothing to do with whether the service was appropriate. The claim itself has a data problem that stopped the system from processing it. Fixing them is usually straightforward once you identify the bad field.

CARC 16: The claim lacks information needed for processing, or contains a billing error. This is a catch-all that could mean anything from a missing diagnosis code to an incomplete provider address.¹
CARC 18: The claim is an exact duplicate of one already submitted.¹
RARC M77: The place of service code is missing, incomplete, or invalid.⁵
EOB 1100 (Arkansas internal): The National Provider Identifier submitted on the claim doesn’t match the Arkansas Medicaid ID associated with the billing provider. Confirm your NPI is correctly linked to your Medicaid enrollment and that the right combination is on the claim.

CARC 18 duplicates usually happen when a claim is submitted twice or when a provider resubmits a corrected claim as a new claim rather than using the proper replacement frequency code. If you need to correct a claim, use frequency code 7. Submitting fresh will almost always trigger the duplicate denial.

CARC 29 means the filing deadline has passed.¹ Arkansas Medicaid requires claims to be filed within 12 months of the date of service, and that deadline applies to every claim type with no exceptions, including retroactive eligibility situations and Medicare crossover claims.³ A CARC 29 denial is essentially unrecoverable.

Prior Authorization Denials

Certain surgical and medical procedures require prior authorization through the Arkansas Foundation for Medical Care (AFMC). If you performed a procedure that needed authorization but didn’t obtain it, the claim comes back denied.⁶

CARC 197 is the standard denial for a missing or absent precertification or authorization.¹ First, confirm the service actually required prior authorization under Arkansas Medicaid policy. If it did and you forgot, you’ll generally need to request a retroactive authorization if the program allows it for that service, or absorb the cost.

To request prior authorization from AFMC, you need the patient’s Medicaid number, the CPT code, all relevant diagnoses, and clinical documentation of medical necessity. If AFMC denies the request, you have 35 calendar days from the date on the denial letter to request reconsideration in writing, with the denial letter and additional documentation attached. One reconsideration per request.⁶

Service and Coverage Denials

Service-level denials relate to whether the treatment itself is covered or was billed correctly. These require a deeper look at Arkansas Medicaid’s coverage policies rather than just fixing a data field.

CARC 96: The charge is not covered. The service either isn’t a Medicaid benefit at all or isn’t covered under the circumstances billed.
CARC 97: The service is bundled into the payment for another procedure already paid on the same claim.¹
CARC 7: The procedure or revenue code doesn’t match the patient’s gender.¹
CARC 9: The diagnosis is inconsistent with the patient’s age.¹

CARC 7 and CARC 9 are often data-entry mistakes. A gender field coded wrong in your practice management system, or a diagnosis pulled from the wrong chart, will trigger these every time. Check demographics before assuming the claim is truly non-payable.

For CARC 97, sometimes adding the correct modifier (modifier 59 for a distinct procedural service, for example) unbundles the services and allows separate payment. Other times, the service genuinely is included in the primary procedure’s reimbursement and no modifier will change that. Check the Arkansas Medicaid policy manual for the specific procedure before resubmitting.

Correcting and Resubmitting a Denied Claim

Once you’ve identified the code and fixed the underlying problem, resubmit within the 12-month window from the original date of service. That window applies to resubmissions and adjustments just as it does to first-time claims.³

When resubmitting electronically, use claim frequency code 7 (replacement of prior claim) and include the original claim’s 13-digit Internal Control Number (ICN) from the RA. To cancel a claim entirely rather than correct it, use frequency code 8 (void/cancel prior claim).⁷ Submitting a corrected claim as new will typically trigger a duplicate denial under CARC 18.

For payment adjustments where a claim was underpaid, overpaid, or paid with incorrect information, use the Adjustment Request Form (HP-AR-004) and mail it to Gainwell Technologies at P.O. Box 8036, Little Rock, Arkansas 72203. The form requires the 13-digit ICN, your provider ID and taxonomy code, the patient’s 10-digit Medicaid ID, the RA date, dates of service, billed and paid amounts, and a specific written description of the problem. Missing any required field and Gainwell will return it without processing.⁸

When to Request Reconsideration or Appeal

When a correction won’t resolve the problem because you believe the denial itself was wrong on the merits, Arkansas Medicaid uses a two-step dispute process: administrative reconsideration followed by a formal appeal.

Administrative Reconsideration

You have 30 calendar days from receiving notice of the denial to request administrative reconsideration. The 30-day clock starts five days after the date on the written notice. The request must be in writing and include a copy of the denial notice along with supporting documentation such as medical records establishing medical necessity.⁹

Formal Appeal

If reconsideration upholds the denial, you can file a formal appeal within 10 calendar days of receiving the reconsideration decision. If you skip the reconsideration step, the appeal deadline is 30 calendar days from the original denial notice. The appeal must be in writing and must identify which findings or decisions you’re challenging and why they conflict with applicable law or professional standards. Appeals go to the Arkansas Department of Health, Office of Medicaid Provider Appeals.⁹

Prior authorization denials follow a different track. Those reconsideration requests go to AFMC within 35 calendar days of the denial letter, not to Gainwell or the Office of Medicaid Provider Appeals.⁶ Missing any of these deadlines forfeits the right to dispute, so tracking the notice date on every denial is worth building into the billing workflow.

1
X12. Claim Adjustment Reason Codes
2
X12. Remittance Advice Remark Codes
3
Cornell Law Institute. Arkansas Code R 024 – SecIII-2-17 Billing
4
AFMC. Third-Party Liability
5
CMS. Pub 100-04 Medicare Claims Processing
6
AFMC. Prior Authorization – Arkansas Medicaid Review Services
7
ResDAC. Claim Frequency Code (FFS)
8
Arkansas Department of Human Services. Adjustment Request Form – Medicaid XIX
9
Arkansas Department of Human Services. Medicaid Administrative Reconsiderations and Appeals