Top Denials and Solutions - Q4 2025

October, November and December of 2025

This article highlights the top five quarterly claim denials and their key solutions for Part B Jurisdiction E, along with the most common front‑end rejections and how to prevent them. It also summarizes frequent call center inquiries and recurring Medical Review errors to help identify patterns that lead to avoidable denials. These resources and best practices can be utilized to support accurate claim submission and reduce future denials.

Invalid Credentials
(CO-B7, N570)

Confirm provider enrolled on date of service.

Verify correct Clinical Laboratory Improvement Amendment (CLIA) number submitted on claim

Duplicate Claim or Service
(CO-97 and CO-B20, N111)

Allow 30 days from first submission before resubmitting.

Check claim status in Noridian Medicare Portal (NMP)

Medical Necessity
(CO-50, N115)

View Active LCDs to verify diagnosis codes that support medical necessity

Non-covered or statutorily excluded
(PR-96, N425)

Patient responsibility because Medicare does not cover services

Qualifying other service/procedure has not been received/adjudicated
(CO-B15, M80)

Patient responsibility because Medicare does not cover services

Top Electronic Data Interchange (EDI) Front-End Rejections and Possible Solutions

National Provider Identifier (NPI) and/or Billing Provider’s Tax ID

Check Provider Enrollment, Chain, and Ownership System (PECOS) Rendering NPI number and ensure NPI matches Tax ID

Diagnosis error for service(s) rendered

Review ICD-10 codes. If related to a policy, check coverage

Invalid HCPCS or CPT codes

Check current HCPCS or CPT book for valid codes and descriptions. Check Medicare fee schedule to verify validity

Invalid subscriber's contract or member number

Verify EDI submitter ID

Top Provider Call Center Inquiries and Solutions

Duplicate claims

Utilize NMP and Review CMS Medically Unlikely Edits (MUE) spreadsheet

Terminated Medicare Beneficiary Identifier (MBI) or Part B effective date

Utilize NMP

Medicare Secondary Payer (MSP)

Review NMP Eligibility for primary payer and utilize MSP webpage

National Correct Coding Initiative (NCCI) Procedure to Procedure Edits (PTP)

Utilize Noridian’s NCCI PTP Lookup Tool

Health Maintenance Organization (HMO)

Review NMP Eligibility before billing

Resources

Last Updated Mar 09 , 2026