Electrodiagnostic (EDX) Medicine is a well-known method of diagnostic analysis that is the target of significant scrutiny.  This is, in part, due to some rather notable abuses.  Nonetheless, even providers who perform these services legitimately are likely to be scrutinized.  As such, providers must be certain that each service ordered and performed is well justified, documented, and coded properly.  As is the case with any service, proper documentation and coding of EDX testing services will allow you to avoid the potential of an adverse post payment action as well as improve your ability to obtain consistent and appropriate reimbursement for these services.

Necessity 
There is no question that EDX testing offers significant reimbursement potential.  Because of this, there have been notable abuses on the part of some providers that have raised the level of carrier scrutiny.  Diagnostic testing was once one of the few services that seemed almost automatically "necessary" and payment was made almost without question.  This is no longer the case.  The lack of control led to abuse and those abuses have forced the pendulum to swing to the opposite extreme.  Carriers now question the need for EDX testing routinely and have either adopted the bundling rules of CCI or have developed bundling rules of their own to limit payment.  Additionally, as most of the questions regarding the appropriateness of the tests performed follow, rather than precede payment, providers should not take any solace in a carrier's previous pattern of unquestioned payment.  As such, for those who perform these services, EDX testing has become a substantial post-payment risk area and because of the substantial reimbursement potential of these services, a ripe post-payment recovery pool.

To avoid liability, providers must establish objective criterion that details when a test will be performed.  When a patient meets appropriate criteria, it is important to explicitly document the clinical rationale supporting the need for the test.  Following testing, there should be evidence that the provider reviewed the test results and relied on them in rendering a diagnosis or formulating a plan of treatment for the patient. Providers should avoid routine patterns of study that involve the use of the same codes in the same number of units for each and every patient.  Instead, the scope of the EDX test and the types of tests performed should be tailored to the specific diagnostic needs of each case. 

Having a better understanding of each of the various EDX studies will help you not only with code selection, but will also assist with your ability to effectively screen patients for EDX testing and document the appropriate rationale.  Where tests are performed, documented, and coded correctly, your ability to secure and retain reimbursement is assured.  Fortunately, the AMA, in conjunction with the AAEM (American Association of Electrodiagnostic Medicine) and the AAN (American Academy of Neurology), has developed guidelines (AAEM/AAN Guidelines) for the conduct of EDX testing.  These guidelines were published by the AMA in its CPT Assistant.

Scope of Electrodiagnostic Medicine
As described by the AMA, "[e]lectrodiagnostic medicine includes a variety of electrodiagnostic studies, including nerve conduction studies (NCSs) (codes 95900, 95903, and 95904), needle electromyography (EMG) (codes 95860 95861 95863 95864 95867 95868 95869 - 95870), neuromuscular junction (NMJ) testing (code 95937), and other specialized studies. EDX studies are an important means of diagnosing motor neuron diseases, myopathies, radiculopathies, plexopathies, neuropathies, and NMJ disorders (e.g., myasthenia gravis and myasthenic syndrome). EDX studies are also useful when evaluating tumors involving an extremity, the spinal cord, and/or the peripheral nervous system, and in neurotrauma, low-back pain, spondylosis and cervical and lumbosacral disc diseases." 

According to the AMA/AAEM/AAN Guidelines, the reasons for considering EDX testing are as follows:

1. Identify normal and abnormal nerve, muscle, motor or sensory neuron, and NMJ functioning.
2. Localize region(s) of abnormal function.
3. Define the type of abnormal function.
4. Determine the distribution of abnormalities.
5. Determine the severity of abnormalities.
6. Estimate the date of a specific nerve injury.
7. Estimate the duration of the disease.
8. Determine the progression of abnormalities or of recovery from abnormal function.
9. Aid in diagnosis and prognosis of disease.
10. Aid in selecting treatment options.
11. Aid in following response to treatment by providing objective evidence of change in neuromuscular function.
12. Localize correct locations for injection of intramuscular agents.

Coding Guidelines Nerve Conduction Studies (95900 - 95904)
Nerve conduction studies (NCSs) are performed to assess the integrity of, and diagnose diseases of, the peripheral nervous system. Where performed, completion of "indicated" needle EMG studies is also appropriate "to evaluate the differential diagnosis and to complement the NCSs" according to the AAEM/AAN Guidelines.

Additionally, as detailed in the AAEM/AAN Guidelines, "[m]otor, sensory, and mixed NCSs and late responses (F-waves and H-reflex studies) are frequently complementary and performed during the same patient evaluation."   Despite their "complementary nature" there is no CCI or CPT guideline restriction to reporting these services separately although it is noted that it is generally not appropriate to separately report 95900 and 95903 unless these services are performed at unrelated nerve sites.  If this is the case, CPT 95900 would be reported separately with the -59 modifier attached. 

The AAEM/AAN Guidelines suggest that EDX testing reports for NCS services should document the "nerves evaluated, the distance between the stimulation and recording sites, conduction velocity, latency values, and amplitude."   The documentation should also include the rationale for performing the test. 

Units of Service:
As indicated in the code description for the NCS codes (95900 -95904), one unit of service should be reported for "each nerve" tested.  A separate unit of service is also reportable where the testing is performed on "two distinct branches of a given motor or sensory nerve in which both stimulating and recording electrodes are moved to a different location."  American Medical Association, CPT Assistant, CPT 2000 Code and Guideline Changes: A Comprehensive Review,  vol. 9, Iss. 11 (Nov., 1999). 

CCI Edits:
Consistent with the AAEM/AAN guideline instruction that where sensory/motor NCVs are performed, "indicated" needle EMG's are also appropriate, there is no CCI restriction to the reporting of sensory/motor NCV testing (95900-95904) in addition to Needle EMG studies (95860-95872).  Notwithstanding the lack of a CCI bundling/exclusive coding rule, physicians are advised to evaluate carrier policies closely for such restrictions. 

Specific CCI bundling rules for each NCS code are as follows:

95900 - Nerve conduction, amplitude and latency/velocity study, each nerve; motor, without F-wave study

· Bundles into (component of) 95903 and can be unbundled where the -59 is justified.

95903 - Nerve conduction, amplitude and latency/velocity study, each nerve; motor, with F-wave study

· Not a component of any other 95 series code but 95900 and 95920 are components that bundle into 95903 but can be unbundled where the -59 is justified.

95904 - Nerve conduction, amplitude and latency/velocity study, each nerve; sensory

· Is comprehensive to 95808, 95810 and 95811 but these codes can be unbundled from 95904 where the -59 is justified.

Note:   Where a code is comprehensive, component codes bundle into it. Where a code is excluded by the more comprehensive code, the excluded code is disregarded.  According to CCI, in all cases in which when there is a relationship established between a comprehensive and either a component or excluded code, the component or excluded code can be unbundled only where it carries a superscript value of 1.  Where separate reporting is appropriate, modifier -59 or other modifiers are  appended as appropriate to the component or excluded code that is being unbundled and separately reported.  Physicians should exercise caution when unbundling and be certain that the documentation adequately supports the use of modifier -59.

Needle Electromyography (EMG) (95860 - 95870)
According to the AAEM/AAN Guidelines, needle EMG is performed to exclude, diagnose, describe, and follow diseases of the peripheral nervous system and muscle. Needle EMG is "always performed by the physician"   since needle EMG studies are interpreted in real time, as they are being performed. Needle EMG reports should document the muscles tested and the presence and type of spontaneous activity, as well as the characteristics of the voluntary unit potentials.  NOTE: There is no professional/technical split with needle EMG services since the interpretation is included in the service.

Units of Service:
Unlike the NCS codes, the needle EMG codes are specific to the body area, and number of body areas evaluated and do not depend on the number of muscles evaluated.  As a result, needle EMG service codes are not reportable in units; however, these services can be reported in a variety of combinations.  The following instructions are provided by the AMA: "Codes 95860-95864, 95869, and 95870 can be used together in various combinations. For example, to bill for an extensive needle EMG study of one limb and a limited comparison study of the contralateral asymptomatic limb, one would report code 95860 and 95870 together. The modifier '59' could be appended to 95870 to indicate that it is separate and distinct from code 95860 (which refers to another limb)."   

According to the AAEM/AAN Guidelines, codes 95860 - 95864 may be reported only once per patient for a given examination given that they represent complete studies of the extremities.  These codes may appropriately be reported in combination with code 95869 (Needle electromyography; thoracic paraspinal muscles) only if paraspinal muscles between T3-T11 are studied.  Code 95869 may not be billed with code 95860, 95861, 95863, or 95864 if only the muscular associated with the T1 and/or T2 levels are studied when an upper extremity was also studied.  Note that this distinction is not made in the CCI edits below; however, such a distinction is inferable where CCI rules related to use of the -59 modifier are applied where the dermatomal distribution of the nerve roots at T1-T2 is considered.

CCI Edits:
Unlike the NCS codes, there are a number of restrictions in CCI related to separate reporting of various needle EMG studies as follows (Note: code pairings with non-EDX codes exist but are not detailed here.

Check CCI for a complete list of code pairings associated with these codes):

95860 - Needle electromyography; one extremity with or without related paraspinal areas

· Comprehensive to 95869, 95870, 95873 and 95874.  Bundles into 95861, 95863, 95875. These codes can be unbundled where modifier -59 is justified. 

95861 - Needle electromyography; two extremities with or without related paraspinal areas

· Comprehensive to 95860, 95869, 95870, 95873 and 95874.  98961 bundles into 95808, 95810, 95811, 95863, 95864. These codes can be unbundled where modifier -59 is justified.

95863 - Needle electromyography; three extremities with or without related paraspinal areas

· Comprehensive to 95860, 95861, 95869, 95870 95873, 95874and 95920.  This code bundles into 95808, 95810, 95811, 95863, 95864. These codes can be unbundled where modifier -59 is justified. 
95864 - Needle electromyography; four extremities with or without related paraspinal areas

· Comprehensive to 95860, 95861, 95869, 95870 95873, 95874, and 95920.  This code bundles into 95808, 95810 and 95811. These codes can be unbundled where modifier -59 is justified. 

95865 - Needle electromyography; larynx

· Comprehensive to 95873, 95874, and 95920.  These codes can be unbundled where the -59 is justified. This code bundles into no other EDX code. CPT 95865 is considered mutually exclusive to CPT 95867, 95868 and 95870.  These codes may be separately reported where modifier -59 is justified.

95866 - Needle electromyography; hemidiaphragm

· Comprehensive to 95873, 95874, and 95920.  These codes can be unbundled where the -59 is justified. This code bundles into no other EDX code. CPT 95865 is considered mutually exclusive to CPT 95867, 95868 and 95870.  These codes may be separately reported where modifier -59 modifier is justified.

95867 - Needle electromyography; cranial nerve supplied muscle(s), unilateral.  Code 95867 is used for the needle examination of one or more muscles supplied by cranial nerves on one side of the body. Code 95868 is used for the needle examination of one or more muscles supplied by cranial nerves on both sides of the body. These codes should not be reported together and this is supported in the CCI edits as noted below.

· Comprehensive to 95869, 95870, 95873 and 95874 and bundles into 95808, 95810 and 95868. CPT 95867 is also mutually exclusive with 95865 and 95866. These codes can be unbundled where modifier  -59 is justified.

95868 - Needle electromyography; cranial nerve supplied muscles, bilateral

· Comprehensive to 95867, 95869, 95870, 95873 and 95874 and bundles into 95808, 95810 and 95811.  CPT 95868 is also mutually exclusive with 95865 and 95866. These codes can be unbundled where modifier -59 is justified.

95869 - Needle electromyography; thoracic paraspinal muscles (excluding T1 or T12).  Code 95869 should be used when exclusively studying thoracic paraspinal muscles.  Only one unit may be reported, despite the number of levels studied or whether performed unilaterally or bilaterally.

· Comprehensive to 95870, 95873, 95874, and 95920 and bundles into 95860, 95861, 95863, 95864, 95867, 95868 and 95875.  These codes can be unbundled where modifier -59 is justified.

95870 - Needle electromyography; limited study of muscles in one extremity or non-limb (axial) muscles (unilateral or bilateral), other than thoracic paraspinal, cranial nerve supplied muscles, or sphincters

· Comprehensive to 95873 and 95874 and bundles into 95808, 95810, 95811, 95860, 95861, 95863, 95864, 95867, 95868, and 95869. These codes, with the exception of 95874 can be unbundled where modifier -59 is justified.

Somatosensory Evoked Potentials (SEPs) (95925 - 95927)
SEPs are described in the AAEM/AAN guidelines as an extension of the electrodiagnostic evaluation and may be used to test conduction in various sensory fibers of the peripheral and central nervous systems.  As indicated by the code descriptions, SSEP study codes are separated into evaluations of the upper limbs (95925), lower limbs (95926) and the trunk or head (95927). Note: Unlike other EDX test procedures, SSEP is not billed in units per nerve or site tested and the codes for the upper and lower limbs presume bilateral testing.  Where a unilateral upper or lower limb study is performed, the AAEM/AAN Guidelines suggest that 95925 or 95926 (as appropriate) be reported with modifier -52, indicating a reduced service.  

Units:
As noted, CPT 95295-95927 may only be reported once per testing encounter.  Providers should not segregate the service into multiple testing days simply to generate the reporting of additional units of service where it would have been appropriate to perform the entire test in one encounter.
 
CCI Edits
There are no bundling or exclusive CCI edits with respect to other EDX services although SSEP (95925-95927) services are considered components of a great number of codes in the 2XXXX, 5XXXX, and 6XXXX series of codes.  Check CCI for specific code pairings for codes in these series.

Conclusion
While the AAEM/AAN guidelines provide rationale for performance of various EDX studies, these guidelines provide few restrictions for separate reporting of the various EDX test services.  CCI provides more specific bundling criterion; however, most of the restrictions apply within the various codes for a given type of test and there are limited restrictions for performing various types of test such as NCS, Needle EMG and SSEP.  Even where restrictions exist, CCI permits unbundling with modifier -59 in nearly every code-pairing scenario.  Despite this allowance, providers must use modifier -59 cautiously and document the separate nature of the service carefully in order to avoid post payment liability.  Additionally, providers should be aware that overuse of modifier -59 is likely to draw unwanted post-payment audit attention.  Moreover, even where services are not unbundled, a typical EDX examination can result in a substantial number of services and reimbursement value.  This is because NCS test services can be billed in a substantial number of units; and there is generally no bundling restriction where needle EMG and SSEP testing is also performed.  As a result, these studies generally generate substantial reimbursement.  Because of the high reimbursement potential, carriers are likely to scrutinize EDX providers carefully for any evidence of abuse.

About the Author
Michael D. Miscoe, CPC, CHCC, CRA, a certified professional Coder, certified healthcare compliance consultant, and the president of Practice Masters, Inc. He is a member of the National Advisory Board of the American Academy of Professional Coders (AAPC).