ANSI Codes

American National Standard Institute (ANSI) codes are used to explain the adjudication of a claim and are the CMS approved ANSI messages.

Group codes must be entered with all reason code(s) to establish financial liability for the amount of the adjustment or to identify a post-initial-adjudication adjustment. Group codes are not used with REF or MIA/MOA remarks code entries.

PR - Patient responsibility

This signifies the amount that may be billed to the beneficiary or to another payer on the beneficiary's behalf. For example, PR would be used with the reason code for:

  • Beneficiary's deductible or coinsurance
  • The beneficiary assumed financial responsibility for a service not considered reasonable and necessary
  • A charge denied as a result of the beneficiary's failure to supply primary payer or other information
  • Where a beneficiary is responsible for payment of excess non-assigned charges

Charges that have not been paid by Medicare and/or are not included in a PR group are:

  • Late filing penalty (reason code B4)
  • Excess charges on an assigned claim (reason code 45)
  • Excess charges attributable to rebundled services (reason code B15)
  • Charges denied as a result of the failure to submit necessary information
  • Services that are not reasonable and necessary for care (reason code 150) for which there are no indemnification agreements

Note: Suppliers may be subject to penalties if they bill a beneficiary for charges not identified with the PR group code.

CO - Contractual obligation

This includes any amounts for which the supplier is financially liable, such as:

  • Participation agreement violations
  • Assignment amount violations
  • Excess charges by a managed care plan provider
  • Late filing penalties
  • Medical necessity denials/reductions

Note: The beneficiary may not be billed for these amounts.

OA - Other adjustment

This would only be used if neither PR nor CO applied. At least one PR, CO or OA group must appear on each remittance advice. For example, OA would be used when a claim is paid in full at initial adjudication with reason code 23, which is a component of a payment rather than an adjustment to a payment. Neither the beneficiary nor the supplier can be held responsible for any amount classified as an OA adjustment.

CR - Correction to or reversal of a prior decision

This group applies whenever there is a change to a previously adjudicated claim. CR explains the reason for the correction; PR, CO and/or OA must always be used in tandem with CR to show the revised information. Separate reason code entries must be used for the CR group entry and any other groups that apply to the readjudicated claim.

At least one reason code is always used with a group code. The contractor always enters the reason code(s) and that amount from the initial remittance advice for the service being corrected with the CR, and includes any additional reason code that may apply to the subsequent adjustment.


Last Updated Sep 30 , 2022