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N579 Remark Code: Medical Payments Coverage (MPC)

N579 means the payment or adjustment on this line was processed under Medical Payments Coverage (MPC), a benefit on some auto and premises policies that pays reasonable medical expenses after an accident up to a set limit. The paired CARC explains the actual outcome.

Quick facts

Code
N579 (RARC N579)
Status
Active In use since July 15, 2013.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): An MPC fee or policy adjustment the provider must accept, where state rules or agreements make it binding.
  • PR (Patient Responsibility): The patient may owe the amount, for example once the MPC limit is reached, subject to state rules.
  • OA (Other Adjustment): Used when the amount is expected to be considered by another payer.
Official description
Medical Payments Coverage (MPC).
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N579 means

Medical Payments Coverage, often shortened to MedPay or MPC, is a benefit that pays accident-related medical costs up to a fixed limit. It is common on auto policies and also appears on some homeowner’s and business policies. N579 tells you the line was handled under that benefit.

On its own, N579 is informational. The group code and CARC (usually P21, P22, or P23) tell you whether the amount was paid, reduced, or denied.

Things to know about MPC claims

  • Limits are usually modest, so a single episode of care can use up the benefit. When it runs out, the balance moves to other coverage.
  • State rules shape payment. Some jurisdictions apply fee schedules or reasonableness standards to MPC.
  • Several people may share a policy’s MPC limit when they are injured in the same accident, depending on the policy.

What to do

  1. Read the paired CARC to learn the actual action.
  2. Track the remaining MPC benefit with the adjuster, and ask when it is close to exhausted.
  3. Set up the next payer by collecting the patient’s health insurance early, then bill it when MPC stops paying.
  4. Dispute reductions through the carrier’s process if the allowance conflicts with applicable state rules.

For multi-payer situations, see coordination of benefits denials.

Codes that may appear with N579

  • CO-P21 (Payment denied based on the Medical Payments Coverage (MPC) and/or Personal Injury Protection (PIP)): Denied under MPC or PIP jurisdictional regulations or payment policies.
  • CO-P22 (Payment adjusted based on the Medical Payments Coverage (MPC) and/or Personal Injury Protection (PIP)): Adjusted under MPC or PIP jurisdictional regulations or payment policies.
  • CO-P23 (Medical Payments Coverage (MPC) or Personal Injury Protection (PIP)): An MPC or PIP fee schedule adjustment.
  • N577 (Personal Injury Protection (PIP)): Identifies Personal Injury Protection coverage instead of MPC.
  • N587 (Policy benefits have been exhausted.): Policy benefits have been exhausted.
  • N651 (No Personal Injury Protection/Medical Payments Coverage on the policy at the time of the loss.): No PIP or MPC was on the policy at the time of loss.

N579 FAQ

How is MPC different from PIP?

Both pay accident-related medical bills. MPC is usually a smaller medical-only benefit, while PIP, where required by state no-fault laws, may also cover lost wages and other costs. Details vary by state and policy.

Does MPC apply to homeowner's claims too?

Some homeowner's and commercial premises policies include medical payments coverage for guests injured on the property. N579 can appear on those claims as well.

Is MPC primary over health insurance?

It depends on the policy and state coordination rules. Ask the carrier and the patient's health plan how they coordinate.