Clinical UM Guideline

This document addresses the use of electromyography (EMG) and nerve conduction studies (NCS) in the outpatient setting. Needle EMG and NCS typically comprise the electrodiagnostic evaluation of function of the motor neurons, nerve roots, peripheral nerves, neuromuscular junction and skeletal muscles. This document also addresses neuromuscular junction testing regardless of place of service.

Note: For information about other related topics, see:

• CG-MED-50 Visual, Somatosensory and Motor Evoked Potentials
• CG-SURG-112 Carpal Tunnel Decompression Surgery
• MED.00082 Quantitative Sensory Testing
• MED.00092 Automated Nerve Conduction Testing

Medically Necessary:

1. Needle EMG when performed with NCS at the same time of testing are considered medically necessary for diagnosing neuropathy with sensory loss, weakness or muscle atrophy for any of the following indications (1 through 5):
   1. Unexplained peripheral neuropathy with pain of a neuropathic pattern, demonstrated sensory loss, or motor loss on physical examination; or
   2. Neuropathy suspected to be due to trauma; or
   3. When test results are expected to guide the management of conditions known to cause neuropathy, including but not limited to (a through d):
      1. HIV-positive individuals with symptoms of neuropathy; or
      2. Mononeuropathies, such as Bell’s palsy of the facial nerve; or
      3. Diabetics with persistent or progressive symptoms refractory to conventional treatments; or
      4. Individuals on dialysis or those considering dialysis;
         or
   4. Suspected neural impingement or entrapment where symptoms are persistent or unresponsive to initial conservative treatments, as indicated by any of the following (a through g)
      1. Carpal tunnel syndrome (when clinical documentation shows impingement symptoms refractory to activity modification and at least 4 weeks of wrist splint use)*; or
      2. Ulnar neuropathy at the elbow or wrist (when clinical documentation shows impingement symptoms refractory to activity modification and at least 4 weeks of elbow pad use)*; or
      3. Cervical or lumbar radiculopathy (when clinical documentation shows 4-6 weeks of failed conservative therapy, including physical therapy and where the etiology of the radicular symptoms is not explained by MRI or other diagnostic studies); or
      4. Tarsal tunnel syndrome (when clinical documentation shows pain and numbness isolated to the foot); or
      5. Peroneal palsy with foot drop; or
      6. Suspected brachial or lumbosacral plexus impingement; or
      7. Other peripheral nerve entrapment syndromes;
         or
   5. Significant clinical suspicion for any of the following conditions (a through g):
      1. Amyotrophic lateral sclerosis; or
      2. Guillain-Barre syndrome; or
      3. Hereditary myopathies, (for example, muscular dystrophy); or
      4. Hereditary neuropathies, (for example, Charcot-Marie-Tooth disease); or
      5. Inflammatory myopathies, (for example, polymyositis, chronic inflammatory demyelinating polyneuropathy [CIDP]); or
      6. Inflammatory or idiopathic brachial or lumbosacral plexopathy; or
      7. Post-polio syndrome.

*Note: In cases of carpal tunnel syndrome or ulnar neuropathy, the requirement for a period of conservative treatment may be waived if the physical exam demonstrates significant atrophy or weakness or sensory loss.

2. Needle EMG when performed with NCS at the same time of testing are considered medically necessary for diagnosis of individuals with significant clinical suspicion for any of the following neuromuscular junction diseases (1 through 3):
   1. Myasthenia gravis; or
   2. Eaton-Lambert syndrome; or
   3. Botulism.
       
3. NCS performed without needle EMG at the same time of testing is considered medically necessary for any of the following clinical indications (1 through 7):
   1. Evaluation of suspected carpal or tarsal tunnel syndrome; or
   2. Evaluation of suspected acute nerve injury (that is within 3 weeks of occurrence); or
   3. For individuals on anticoagulant therapy (not merely anti-platelet treatments); or
   4. For individuals with significant lymphedema; or
   5. Evaluation of suspected peroneal palsy; or
   6. Evaluation of thoracic outlet syndrome; or
   7. For facial nerve monitoring in Bell’s palsy.

4. Needle EMG performed without NCS at the same time of testing is considered medically necessary for the evaluation of suspected radiculopathy.

Not Medically Necessary:

Needle EMG performed with NCS at the same time of testing are considered not medically necessary when the criteria listed above are not met, including as a screening tool for the general population, in the absence of related symptoms.

NCS performed without needle EMG at the same time of testing is considered not medically necessary except the limited clinical indications listed above.

Needle EMG performed without NCS at the same time of testing is considered not medically necessary when the criteria listed above are not met.

Testing for neuromuscular junction diseases with needle EMG or NCS is considered not medically necessary when the criteria above are not met, and for all other indications.

Needle EMG or NCS is considered not medically necessary for all other conditions, including but not limited to, back pain without radiculopathy, or headaches when there is no suspicion of an underlying disorder of the cranial nerves.

The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services may be Medically Necessary when criteria are met:

When services are Not Medically Necessary:
For the procedure codes listed above when criteria are not met or for situations designated in the Clinical Indications section as not medically necessary.

Summary:

Electromyography (EMG) and nerve conduction studies (NCS) are electrodiagnostic tools used to assess the functional integrity of the motor neuron, nerve root, peripheral nerve, neuromuscular junction, and muscle. EMG involves needle electrode insertion to record muscle electrical activity, aiding in the differentiation of various neuromuscular disorders, including inflammatory, chronic, and inherited myopathies, and acute vs. chronic denervation. NCS uses surface electrodes (occasionally needles for deep nerves) to evaluate neuropathies and determine sensory vs. motor involvement and axonal vs. demyelinating patterns. The American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) recommends combined use of EMG and NCS in most cases for diagnostic accuracy. Optimal use of EMG/NCS relies on clinical context and physician-guided test selection based on history, examination, and diagnostic suspicion.

Discussion:

In EMG, electrical potentials are detected by a needle electrode inserted directly into a skeletal muscle. This test is useful in the outpatient evaluation of the motor neuron, nerve root, peripheral nerve, neuromuscular junction and the muscle itself. It is helpful in distinguishing between inflammatory and chronic, metabolic or inherited muscle diseases, and in differentiating between acute, recovering, and chronic denervation. While EMG may not necessarily provide a clinical diagnosis, patterns of EMG abnormalities may suggest specific pathologic entities.

NCS performed in the outpatient setting provides information regarding the presence, severity, and location of a peripheral neuropathy, mononeuropathy, or disorders affecting the neuromuscular junction. Additional information suggested by NCS includes the functional modality most involved (sensory or motor) and the predominant pattern of pathology, (for example, axonal, demyelinating, or both).

EMG and NCS tests require needle insertion and then repositioning at multiple sites and at anatomically critical areas, in order to assist in clinical diagnosis, prognosis, and clinical management decisions. In NCS, surface electrodes are usually used for both stimulation and recording of the electrical responses. However, needle electrodes are sometimes needed to evaluate a deep nerve, such as the sciatic or the femoral nerve.

EMG and NCS are most effective when preliminary investigation (including history and neurologic examination) is suggestive of a significant probability of pathology. EMG and NCS should be performed and interpreted by individuals with appropriate training and expertise and should be evaluated in the context of the individual clinical scenario.

The AANEM, states in their “Recommended Policy for Electrodiagnostic Medicine” (2017), that the selection of the number and type of specific EMG and NCS tests to be performed on an individual is best determined by the testing physician, based on multiple factors, including: the referral diagnosis, presenting symptoms, medical history, findings on prior clinical examination or diagnostic testing, and suspected etiology. In 2023, AANEM updated this position statement which states:

Electrodiagnostic testing is used to evaluate the integrity and function of the peripheral nervous system (most cranial nerves, spinal roots, plexi, and nerves), neuromuscular junction (NMJ), muscles, and the central nervous system (brain and spinal cord). Electrodiagnostic testing is performed as part of an electrodiagnostic evaluation for diagnosis or as follow-up of an existing condition. Electrodiagnostic studies can provide information to:

• Identify normal and abnormal nerve, muscle, motor or sensory neuron, and NMJ functioning.
• Localize region(s) of pathology.
• Characterize the pathology.
• Determine the distribution of abnormalities.
• Determine the severity of abnormalities.
• Estimate the chronology of the disease.
• Determine the progression and/or recovery from abnormal function.
• Aid in diagnosis and prognosis of disease.
• Aid in selecting treatment options.
• Aid in following response to treatment by providing objective evidence of change in neuromuscular function.
• Localize correct locations for injection of intramuscular agents (e.g., botulinum toxin).

In the 2020 position statement “Proper Performance and Interpretation of Electrodiagnostic Studies”, AANEM states that except for unique situations, needle EMG and NCS should be performed together in a study design determined by a trained physician, in order that healthcare decisions are based on complete diagnostic information. The AANEM position statement also reiterated the importance of the physician performing a history and physical prior to any testing and designing the NCS and EMG testing based upon the information obtained during that exam. Some excerpted comments follow:

Because needle EMG studies offer information needed for an accurate diagnosis, except in unique situations, it is the AANEM's position that NCSs and needle EMGs should be performed together in the same setting. It is the opinion of the AANEM that utilizing only NCSs provides incomplete diagnostic information, potentially leading to inadequate or inappropriate treatment (including inappropriate surgery) and increased health care costs.

Using a predetermined or standardized battery of NCSs for all patients is inappropriate because it may be possible to obtain the data needed to reach a diagnosis with fewer studies. Alternatively, a pre-determined battery may not include the appropriate NCSs and/or EMG tests to determine the diagnosis.

In another AANEM document, the “Model Policy for Needle Electromyography and Nerve Conduction Studies”, updated in 2016, the following was noted:

The necessity and reasonableness of the following uses of needle EMG studies have not been established:

1. exclusive testing of intrinsic foot muscles in the diagnosis of proximal lesions
2. definitive diagnostic conclusions based on paraspinal EMG in regions bearing scar of past surgeries (e.g., previous laminectomies)
3. pattern-setting limited limb muscle examinations, without paraspinal muscle testing for a diagnosis of radiculopathy
4. needle EMG testing shortly after trauma, before needle EMG abnormalities would have reasonable time to develop
5. surface and macro EMGs
6. multiple uses of needle EMG in the same patient at the same location for the purpose of optimizing botulinum toxin injections.

Current literature does not support the use of EMG and NCS for conditions like headaches without suspected cranial nerve involvement or back pain without suspected radiculopathy, as these tests do not provide meaningful diagnostic value in such cases.

Carpal Tunnel Syndrome

The 2023 AANEM Recommended Policy for Electrodiagnostic Medicine in patients suspected of CTS, states that the following studies are recommended:

• Perform a median sensory NCS across the wrist with a conduction distance of 13 cm to 14 cm. If the result is abnormal, comparison of the result of the median sensory NCS to the result of a sensory NCS of one other adjacent sensory nerve in the symptomatic limb (Standard).
• If the initial median sensory NCS across the wrist has a conduction distance greater than 8 cm and the result is normal, one of the following additional studies is recommended:
  • comparison of median sensory or mixed nerve conduction across the wrist over a short (7 cm to 8 cm) conduction distance with ulnar sensory nerve conduction across the wrist over the same short (7 cm to 8 cm) conduction distance (Standard), or
  • comparison of median sensory conduction across the wrist with radial or ulnar sensory conduction across the wrist in the same limb (Standard), or
  • comparison of median sensory or mixed nerve conduction through the carpal tunnel to sensory or mixed NCSs of proximal (forearm) or distal (digit) segments of the median nerve in the same limb (Standard).
• Motor NCS of the median nerve recording from the thenar muscle and of one other nerve in the symptomatic limb to include measurement of distal latency (Guideline).
• Supplementary NCS: comparison of the median motor nerve distal latency (second lumbrical) to the ulnar motor nerve distal latency (second interossei); median motor terminal latency index; median motor nerve conduction between wrist and palm; median motor nerve compound muscle action potential wrist-to-palm amplitude ratio to detect conduction block; median sensory nerve action potential wrist to-palm amplitude ratio to detect conduction block; short segment (1 cm) incremental median sensory nerve conduction across the carpal tunnel (Option).
• Needle electromyography of a sample of muscles innervated by the C5 to T1 spinal roots, including a thenar muscle innervated by the median nerve of the symptomatic limb (Option).

The AANEM 2023 position statement does not recommended the following tests for confirmation of CTS: multiple median F-wave parameters, median motor nerve residual latency, or sympathetic skin response, due to inferior sensitivity and specificity compared to standard studies. Additionally, median nerve conduction studies using the following methods: limb ischemia, dynamic hand exercises, or brief or sustained wrist positioning are not recommended due to inferior diagnostic accuracy or lack of established clinical efficacy compared to standard electrodiagnostic tests.

In 2024 the American Academy of Orthopedic Surgeons (AAOS) updated their “Management of Carpal Tunnel Syndrome Evidence-Based Clinical Practice Guidelines.” Regarding using the Carpal Tunnel Syndrome-6 (CTS-6) evaluation tool their guidance states:

Strong evidence suggests that CTS-6 can be used to diagnose carpal tunnel syndrome, in lieu of routine use of ultrasonography or NCV/EMG.
Quality of Evidence: High.
Strength of Recommendation: Strong

AAOS based there recommendations upon the findings in 10 high and 5 moderate quality studies supporting the use of either the CTS-6, NCV/EMG, or ultrasonography. Although there was heterogeneity present in both the study populations and comparisons for the different studies, there was strong and consistent evidence supporting all modalities in diagnosing CTS. There was no evidence of clinical superiority between diagnostic tools, therefore the guideline does not promote one test over another or change previous recommendations for NCV/EMG testing.

In 2019, Callaghan published a cross-sectional observational study that analyzed testing patterns in incident peripheral neuropathy. A random national sample of 83693 Medicare claims data was analyzed. Diabetes prevalence was 59% (n=46,476). The inclusion criteria were age greater than or equal to 65 years, no diagnosis of peripheral neuropathy in the 30 months prior, and continuous Medicare enrollment 30 months before and 6 months after the incident peripheral neuropathy diagnosis. The tests utilized were vitamin B₁₂: 28.3%, SPEP (serum protein electrophoresis) 13.4%, fasting glucose 10.6%, glucose tolerance test (GTT) 1.0%, hemoglobin A1c 50.3%, EMG: 22.6%, and MRI 25.7%. The results demonstrated that persistent overuse of EMGs and MRIs continued at high rates with incremental increases over time despite their limited impact on management. Concurrently, there was continued underuse of SPEP and GTT, which are recommended by AAN guidelines for identifying reversible causes of peripheral neuropathy. The study was limited by restricted generalizability beyond the Medicare population, the lack of data on test appropriateness, and potential misclassification bias due to reliance on claims data. The author concluded that despite robust clear guideline recommendations, the diagnostic approach to peripheral neuropathy remains suboptimal, and that clinical practice has not significantly shifted toward guideline-concordant testing strategies, with persistent overuse of neurodiagnostic procedures and underuse of simple, recommended blood tests. The author emphasized the need for system-level quality improvement strategies including peer comparison mechanisms within the electronic health record to curb EMG/MRI overuse, and the development of order sets in electronic health records promoting guideline-concordant testing.

Peer Reviewed Publications:

1. Callaghan BC, Price RS, Feldman EL. Distal symmetric polyneuropathy: a review. JAMA. 2015; 314(20):2172-2181.
2. Callaghan BC, Reynolds EL, Muthukumar L, et al. Diagnostic testing for patients with peripheral neuropathy. JAMA Neurol. 2025; 82(4):420-1.
3. Chang MH, Liu LH, Lee YC, et al. Comparison of sensitivity of transcarpal median motor conduction velocity and conventional conduction techniques in electrodiagnosis of carpal tunnel syndrome. Clin Neurophysiol. 2006; 117(5):984-991.
4. Dabbagh A, MacDermid JC, Yong J, et al. Diagnostic accuracy of sensory and motor tests for the diagnosis of carpal tunnel syndrome: a systematic review. BMC Musculoskelet Disord. 2021; 22(1):337.
5. Gooch CL, Weimer LH. The electrodiagnosis of neuropathy: basic principles and common pitfalls. Neurol Clin. 2007; 25(1):1-28.
6. Katz JN, Simmons BP. Carpal tunnel syndrome. N Engl J Med. 2002; 346(23):1807-1812.
7. Lazaro RP. Electromyography in musculoskeletal pain: A reappraisal and practical considerations. Surg Neurol Int. 2015; 6:143.
8. Megerian JT, Kong X, Gozani SN. Utility of nerve conduction studies for carpal tunnel syndrome by family medicine, primary care, and internal medicine physicians. J Am Board Fam Med. 2007; 20(1):60-64.
9. Mendell JR, Sahenk Z. Clinical Practice. Painful sensory neuropathy. N Engl J Med. 2003; 348(13):1243-1255.
10. Mondelli M, Aretini A, Arrigucci U, et al. Clinical findings and electrodiagnostic testing in 108 consecutive cases of lumbosacral radiculopathy due to herniated disc. Neurophysiol Clin. 2013; 43(4):205-215.
11. Tankisi H, Pugdahl K, Euglsang-Frederiksen A, et al. Pathophysiology inferred from electrodiagnostic nerve tests and classification of polyneuropathies. Suggested guidelines. Clin Neurophysiol. 2005; 116(7):1571-1580.

Government Agency, Medical Society, and Other Authoritative Publications:

1. American Academy of Neurology (AAN), American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) and the American Academy of Physical Medicine and Rehabilitation (AAPM&R). Practice parameter: Electrodiagnostic studies in ulnar neuropathy at the elbow. Neurology. 1999; 52(4):688-690.
2.  American Academy of Orthopaedic Surgeons (AAOS), Management of Carpal Tunnel Syndrome. Evidence-Based Clinical Practice Guideline. May 18, 2024. Available at: https://www.aaos.org/globalassets/quality-and-practice-resources/carpal-tunnel/carpal-tunnel-2024/cts-cpg.pdf. Accessed on June 2, 2025.
3. American Association of Electrodiagnostic Medicine, American Academy of Neurology, and American Academy of Physical Medicine and Rehabilitation. Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: summary statement. Muscle Nerve. 2002; 25(6):918-22.
4. American Association of Electrodiagnostic Medicine; So YT. Guidelines in electrodiagnostic medicine. Practice parameter for needle electromyographic evaluation of patients with suspected cervical radiculopathy. Muscle Nerve Suppl. 1999;8:S209-21. Reaffirmed 2020.
5. AANEM. Available at: https://www.aanem.org/clinical-practice-resources. Accessed on June 2, 2025.
   • AANEM Policy Statement on Electrodiagnosis for Distal Symmetric Polyneuropathy. Approved July 2017.
   • Model Policy for Needle Electromyography and Nerve Conduction Studies. Updated and reapproved December 2022.
   • Proper Performance and Interpretation of Electrodiagnostic Studies. Muscle Nerve. 2020; 61(5):567-569.
   • Recommended Policy for Electrodiagnostic Medicine. Updated January 2023. Endorsed by the American Academy of Neurology (AAN), the American Academy of Physical Medicine and Rehabilitation (AANEM).
   • Referral Indications for Primary Care Providers. January 7, 2020.
   • Reporting the results of needle EMG and nerve conduction studies: An educational report. Updated and approved August 2019.
6. Cho SC, Ferrante MA, Levin KH, Harmon RL, So YT. Utility of electrodiagnostic testing in evaluating patients with lumbosacral radiculopathy: an evidence-based review. Muscle Nerve. 2010; 42(2):276-282. Reaffirmed 2017.
7. England JD, Gronseth GS, Franklin G, et al. Distal symmetric polyneuropathy: a definition for clinical research: report of the American Academy of Neurology (AAN), the American Association of Neuromuscular and Electrodiagnostic Medicine (AAEM) and the American Academy of Physical Medicine and Rehabilitation (AAPM&R). Neurology. 2005; 64(2):199-207.
8. Kang PB, McMillan HJ, Kuntz NL, et al; Professional Practice Committee of the American Association of Neuromuscular & Electrodiagnostic Medicine. Utility and practice of electrodiagnostic testing in the pediatric population: An AANEM consensus statement. Muscle Nerve. 2020; 61(2):143-155.
9. Marciniak C, Armon C, Wilson J, Miller R. Practice parameter: utility of electrodiagnostic techniques in evaluating patients with suspected peroneal neuropathy: an evidence-based review. Muscle Nerve. 2005; 31(4):520-527. Reaffirmed October 2020.

1. American Academy of Orthopaedic Surgeons (AAOS). OrthoInfo: Electrodiagnostic Testing. Last reviewed March 2023. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=a00270. Accessed on June 2, 2025.
2. National Institute of Health (NIH). National Library of Medicine. Medical Tests. Electromyography (EMG) and Nerve Conduction Studies. Last updated April 10, 2024. Available at: https://medlineplus.gov/lab-tests/electromyography-emg-and-nerve-conduction-studies/. Accessed on June 2, 2025.
3. National Institute of Health (NIH). National Institute of Neurological Disorders and Stroke. Neurological Diagnostic Tests and Procedures Fact Sheet. Last Reviewed April 2019. Available at: https://catalog.ninds.nih.gov/sites/default/files/publications/neurological-diagnostic-tests-procedures.pdf. Accessed on June 2, 2025.

Electromyography, Nerve Conduction Studies
Electrophysiological Studies
EMG/NCS
Nerve Conduction Studies, Electromyography
Nerve Conduction Velocity (NCV) Studies

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