Where this LCD applies
Each contract number is a jurisdiction on the remittance; the policy binds claims processed under these contracts and no others.
Billing and coding: diagnoses and procedure codes
Since 2019 the codes live in the companion article rather than the LCD. Billing and Coding A57597 (Billing and Coding: Somatosensory Testing) carries the diagnosis and procedure lists the contractor loads as the claims edit. CPT codes are shown as bare numbers because the descriptors are licensed by the AMA; HCPCS Level II descriptors are public and shown.
A57597: Billing and Coding: Somatosensory Testing (Billing and Coding, effective 2025-10-01)
- Covered ICD-10-CM codes
- 656
- 3 groups
- Non-covered ICD-10-CM codes
- 0
- Procedure codes listed
- 4
- Full article
- cms.gov record
| ICD-10-CM | Description (FY2027) |
|---|---|
| A18.01 | — |
| C41.2 | — |
| C70.0 | — |
| C70.1 | — |
| C72.0 | — |
| C72.1 | — |
| C72.21 | — |
| C72.22 | — |
| C72.31 | — |
| C72.32 | — |
| C72.41 | — |
| C72.42 | — |
| C72.59 | — |
| C73 | Malignant neoplasm of thyroid gland |
| C79.31 | — |
| C79.32 | — |
| C79.49 | — |
| D21.0 | — |
| D32.0 | — |
| D32.1 | — |
| D33.0 | — |
| D33.1 | — |
| D33.3 | — |
| D33.4 | — |
Procedure codes: 95925, 95926, 95927, 95938.
Coverage indications, limitations and medical necessity
Abstract:
Short-latency somatosensory evoked potentials (SEPs) represent electrophysiologic responses of the somatosensory pathways to stimulation. Somatosensory testing involves the application of a series of brief electrical stimuli over peripheral nerves (e.g., the median, peroneal, and tibial nerves) and recording the resulting evoked potentials over proximal portions of the nerves and central pathways which were stimulated, the plexus, spine and/or scalp. Action potentials recorded from these sites are averaged by a computer to improve signal clarity and then displayed in standard formats on the computer’s screen as well as in printed form.
A provider trained in interpreting clinical evoked potential studies analyzes the waveforms. The waveforms obtained should be described by nerve being stimulated, the recording sites, peak latencies, interpeak intervals (when appropriate), and amplitudes of the significant components. The nerves most commonly stimulated are the median nerve at the wrist for testing in the upper extremity, and the posterior tibial nerve at the ankle or common peroneal nerve (CPN) at the knee for the lower extremity.
SEPs evaluate the entire somatosensory pathway from the site of stimulation up to the cerebral cortex. It is possible to distinguish between lesions located in the peripheral nerve, in the dorsal column spinal cord pathway, or higher centers in the brain up through the cortex. In general, there is no need for SEP in the diagnosis of most peripheral neuropathies because the conventional nerve conduction studies or needle EMG can identify these types of lesions and no added information is obtained from SEP. This local coverage determination discusses medically necessary indications and limitations for SEPs.
Indications:
Medicare will consider the use of short-latency somatosensory evoked potentials to be medically reasonable and necessary to assist in the diagnosis of certain neuropathologic states (as described below) to provide information for treatment decisions and for intraoperative electrophysiological monitoring during spinal surgeries in which there is risk of additional nerve or spinal cord injury. However, it is not anticipated that such monitoring will be medically necessary for the typical cervical or lumbar root decompression procedures.
SEPs are used to evaluate the more proximal segments of nerves and the integrity of the central somatosensory pathways when abnormality of conduction through the brain and/or brainstem, spinal cord, and/or peripheral nerves is suspected. This utilization would include conditions such as multiple sclerosis, cervical spondylosis with myelopathy, coma, spinal cord trauma, myoclonus, Friedreich’s ataxia, syringomyelia, spinal cord tumors, spinal stenosis and other conditions where there is spinal cord compression.
Limitations:
SEP studies are appropriate only when a detailed clinical history and neurologic examination and appropriate diagnostic tests such as imaging studies, electromyogram, and nerve conduction studies make a lesion (or lesions) of the central somatosensory pathways a likely and reasonable differential diagnostic possibility.
Summary of evidence (opening)
N/A
the full summary and analysis of evidence are in the CMS record.
Dates, lineage and related policies
- Original determination effective
- 2015-10-01
- Current revision effective
- 2025-08-28
- Last reviewed by the contractor
- 2025-07-21
- MCD version
- 42
- Derived from
- L32902
The contractor lists one National Coverage Determination as related: NCD 160.23 Sensory Nerve Conduction Threshold Tests (sNCTs). Where an NCD speaks, it controls; the LCD can only address what the NCD leaves open.
Using this policy on a claim
Match the documented indication to the covered indications above before the service is scheduled, carry a diagnosis from the article's covered list on the claim line, and keep the elements the documentation section asks for in the record, because the contractor can request it later through medical review. A denial under this policy arrives as CARC 50 with remark N115; the LCD lookup guide walks through the appeal path and the Advance Beneficiary Notice rules, and the Wisconsin Physicians Service Insurance Corporation hub lists every other active policy from the same contractor.
The same policy title at other contractors
Contractors often adopt each other's policies and then revise them separately, so the criteria and the diagnosis lists drift apart. The topic comparison lines up every version.
Frequently asked questions
What does LCD L34624 cover?
Short-latency somatosensory evoked potentials (SEPs) represent electrophysiologic responses of the somatosensory pathways to stimulation. Somatosensory testing involves the application of a series of brief electrical stimuli over peripheral nerves (e.g., the median, peroneal, and tibial nerves) and recording the resulting evoked potentials over proximal portions of the nerves and central pathways which were… The full indications and limitations are reproduced on this page from the CMS Medicare Coverage Database export of September 24, 2026.
Which states does LCD L34624 apply to?
Wisconsin Physicians Service Insurance Corporation applies it to Medicare claims in AK, AL, AR, AZ, CA, CO, CT, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY. A Local Coverage Determination binds only the contractor that wrote it; the same service in another jurisdiction is judged under that contractor's own policy or, where none exists, claim by claim.
Which diagnosis codes support medical necessity under LCD L34624?
The companion billing and coding article A57597 lists 656 ICD-10-CM codes in 3 groups that support medical necessity; the first 24 appear on this page and the complete list is in the article on cms.gov.
How do I appeal a denial under LCD L34624?
The remittance carries claim adjustment reason code 50 with remark code N115, naming the LCD. Compare the documented indication with the policy's covered indications and the article's diagnosis list, then file a redetermination within 120 days with the record attached; if the service genuinely falls outside the policy, the patient can be billed only when a valid Advance Beneficiary Notice was obtained before the service.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.
- Medicare Coverage Database, current LCD exportVersion MCD release 2026-09-24 · effective 2026-09-20 · file lcd.csvSHA-256 2fcc4251b6ddd1eb…
- Medicare Coverage Database, current Billing and Coding Articles exportVersion MCD release 2026-09-24 · effective 2026-09-20 · file article.csvSHA-256 f31932f1df3b4035…
- ICD-10-CM FY2027 code descriptionsVersion FY2027 · effective 2026-10-01 · file icd10cm_codes_2027.txtSHA-256 3c0583a38ee0e848…
Disclaimer
The policy text and code lists are reproduced from the CMS Medicare Coverage Database export as an operational reference. Verify against the current LCD and article on cms.gov before billing; coverage depends on the full record and the contractor. Not legal, clinical or billing advice.