Denial Code Resolution

View the most common claim submission errors below. Select the applicable Reason/Remark codes to access the denial description, supplier solutions, and how to avoid the same denial in the future.

The Washington Publishing Company publishes the CMS-approved Reason Codes and Remark Codes.

  • Claim Adjustment Reason Codes (CARCs) communicate an adjustment, meaning that they must communicate why a claim or service line was paid differently than it was billed. If there is no adjustment to a claim/line, then there is no adjustment reason code.
  • Remittance Advice Remark Codes (RARCs) are used to provide additional explanation for an adjustment already described by a CARC or to convey information about remittance processing.
Reason Code Remark Code Common Reasons for Denials
4 M114
  • HCPCS code is inconsistent with modifier used or a required modifier is missing
  • Item billed was processed under DMEPOS Competitive Bidding Program and requires an appropriate competitive bid modifier
4 N519
  • HCPCS code is inconsistent with modifier used or required modifier is missing
  • The date of death precedes the date of service.
16 M124
  • Item billed does not have base equipment on file. Main equipment is missing therefore Medicare will not pay for supplies
16 MA13
  • Item(s) billed did not have a valid ordering physician name
16 MA13
  • Item(s) billed did not have a valid ordering physician National Provider Identifier (NPI) registered in Medicare Provider Enrollment, Chain and Ownership System (PECOS)
29 N211
  • The time limit for filing has expired.
  • You may not appeal this decision.
50 M127
  • Documentation requested was not received or was not received timely
50 N115
  • Item billed may require a specific diagnosis or modifier code based on related Local Coverage Determination (LCD)
  • Development letter requesting additional documentation to support service billed was not received within provided timeline
  • Item being billed does not meet medical necessity
96 N115
  • Non-covered charge(s). At least one Remark Code must be provided (may be comprised of either the NCPDP Reject Reason Code, or Remittance Advice Remark Code that is not an ALERT.) Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.
  • This decision was based on a Local Coverage Determination (LCD). An LCD provides a guide to assist in determining whether a particular item or service is covered. A copy of this policy is available at, or if you do not have web access, you may contact the contractor to request a copy of the LCD.
97 M2
  • Beneficiary was inpatient on date of service billed
97 N390
  • HCPCS code billed is included in payment/allowance for another service/procedure that has already been adjudicated
109 N104
  • Claim was submitted to incorrect Jurisdiction
109 N130
  • Claim was submitted to incorrect contractor
109 N418
  • Claim was billed to the incorrect contractor
  • Beneficiary was enrolled in a Medicare Health Maintenance Organization (HMO) for date of service submitted
151 M3
  • Item billed is same or similar to an item already received in beneficiary's history
151 N115
  • There is a date span overlap or overutilization based on related LCD
173 N668
  • Item billed requires an initial Certificate of Medical Necessity (CMN) or DME Information Form (DIF) be submitted
  • Initial CMN or DIF was not submitted with claim or on file with Noridian
176 N592
  • Item billed requires a recertified or revised CMN or DIF to be submitted. Either a CMN/DIF was not submitted or not on file with Noridian
204 N130
  • Noncovered item
  • Item is not medically necessary for DME
A1 N370
  • Oxygen equipment has exceeded number of approved paid rentals
B7 N570
  • This provider was not certified/eligible to be paid for this procedure/service on this date of service.
  • Missing/incomplete/invalid credentialing data.
B18 N522
  • Duplicate claim has already been submitted and processed
B20 M115 N211
  • Procedure/service was partially or fully furnished by another provider.
  • This item is denied when provided to this patient by a non-contract or non-demonstration supplier.


Last Updated Oct 08, 2018