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
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)
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
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


Last Updated May 01, 2018