Aetna EDX Denials: Documentation and Appeal Guidance for Physicians

AANEM has received reports from members regarding denials of NCS and EMG claims for patients covered under Aetna plans, including cases in which services were classified as experimental or investigational when the number of studies performed exceeded thresholds referenced in Aetna's Electrodiagnostic Testing Clinical Policy Bulletin (CPB 0502), which incorporates AANEM's Maximum Numbers of Studies Table and Appendix J guidance.

As these policies continue to affect claim adjudication, it is important for physicians to understand how AANEM's guidance was intended to be used, how studies should be counted, and how documentation can help support medical necessity when additional testing is clinically appropriate.

The Maximum Numbers Table Is Not a Hard Cap

AANEM's Maximum Numbers of Studies Table was developed to describe the number of studies required in approximately 90% of typical clinical cases. The table is based on patients with a single diagnosis and was never intended to function as an absolute limit on medically necessary testing.  Patients often present with complex, atypical, overlapping, or evolving conditions. In addition, many electrodiagnostic evaluations involve multiple diagnostic considerations that are not fully overlapping. In these situations, additional studies beyond the values listed in the table for a single diagnosis may be clinically appropriate to answer the diagnostic question.

Read more for guidance on counting studies under Appendix J, documentation strategies when testing exceeds the Maximum Numbers Table, and practical tips for structuring appeals. 

How Studies Are Counted

Appendix J, of the AMA CPT codebook, provides guidance regarding how nerve conduction studies are counted for reporting purposes and is frequently referenced by payers when reviewing EDX claims.  Appendix J is the primary reference for counting studies. Physicians should be aware that questions occasionally arise regarding both the application of Appendix J and the interpretation of the Maximum Numbers Table, particularly in cases involving multiple diagnoses or diagnostic considerations. Clear documentation can be helpful when supporting appeals involving disputed study counts.  Key principles include:

• Each sensory, motor, or mixed nerve studied is counted as one study.
• Additional segments of the same nerve, including inching studies, do not create additional billable studies.
• Targeted testing of the contralateral limb may be appropriate when clinically necessary for comparison or clarification of finding
• When multiple diagnoses are being considered, the total number of studies should reflect the overall diagnostic evaluation rather than simply adding together table values from multiple conditions.

Documentation Matters

Clear documentation remains one of the most effective tools for supporting appropriate reimbursement. The medical record should clearly describe:

• Relevant history and examination findings
• Working diagnosis or diagnostic considerations
• Clinical rationale for EDX testing
• Nerves and muscles studied
• How the results will influence diagnosis, treatment, or further evaluation

When testing exceeds the Maximum Numbers Table, include a brief explanation of why additional studies were necessary for that specific patient.
Examples may include:

• Need for bilateral comparison
• Multiple overlapping diagnostic considerations
• Atypical or asymmetric findings
• Localization of a lesion requiring evaluation of additional nerves
• Evolving symptoms that expanded the differential diagnosis

Even a concise statement explaining why the case falls outside the typical presentation can be helpful during subsequent review.

 Appeal Checklist

When appealing a denial, physicians should consider including:

✓ Full EDX report with data tables
✓ Related clinic or consultation note
✓ Explanation of the clinical indication for testing
✓ Description of how studies were counted using Appendix J guidance
✓ Explanation of why the number of studies performed was medically necessary

The appeal should explain how the testing addressed the diagnostic question, how studies were counted, and why the number of studies performed was medically necessary for that patient. When applicable, physicians may wish to explain why the clinical presentation fell outside the typical scenarios reflected in the Maximum Numbers Table.

 Help Inform Future Advocacy

AANEM continues to monitor both denial trends and payer application of electrodiagnostic testing policies. Information from members helps identify recurring issues and informs ongoing advocacy efforts with insurers and policymakers.

Members who encounter recurring denial patterns or have questions regarding EDX coverage policies are encouraged to contact policy@aanem.org.