CMS NCD 270 Update: Sensory Nerve Conduction Threshold Tests Remain Noncovered for Medicare

CMS (the Centers for Medicare & Medicaid Services) has issued a modified policy update to National Coverage Determination (NCD) 270, governing Sensory Nerve Conduction Threshold (sNCT) tests. The modification, effective March 12, 2026, reaffirms and formalizes CMS's longstanding position that sNCT testing is not reasonable and necessary for diagnosing sensory neuropathies or radiculopathies in Medicare beneficiaries. For billing teams and RCM directors, this update is a clear signal: claims submitted for sNCT procedures will be denied, and no pathway to coverage exists under current Medicare policy.

What Is an sNCT and Why Does CMS Consider It Noncovered?

The sNCT (Sensory Nerve Conduction Threshold test) is a psychophysical assessment designed to measure both central and peripheral nerve function. Specifically, it measures the detection threshold of accurately calibrated sensory stimuli, with the goal of evaluating and quantifying function in both large and small caliber nerve fibers for the purpose of detecting neurologic disease.

In theory, the procedure can flag dysfunction anywhere along the sensory pathway—from peripheral receptors through the sensory tracts, the primary sensory cortex, and into the association cortex. That broad theoretical reach is part of why the test was initially considered as a diagnostic tool.

However, CMS has consistently concluded that the scientific and clinical evidence supporting sNCT does not meet the "reasonable and necessary" standard under Section 1862(a)(1)(A) of the Social Security Act. The agency first reached this conclusion effective October 1, 2002, and reaffirmed it after a formal reconsideration process effective April 1, 2004.

How sNCT Testing Differs from Covered Nerve Conduction Studies

A critical distinction for billing teams: sNCT testing is not the same as standard nerve conduction studies, and conflating the two is a compliance risk.

Standard nerve conduction studies measure nerve conduction velocity, amplitude, and latency—all of which assess nerve function through objective, physiological parameters. sNCT testing, by contrast, relies on patient perception and threshold detection responses. It is also distinct from short-latency somatosensory evoked potentials, which measure the electrical signal generated by the nervous system in response to stimulation.

This difference matters enormously in billing. Providers may use sNCT devices—including "current output" type devices that perform current perception threshold (CPT), pain perception threshold (PPT), or pain tolerance threshold (PTT) testing, as well as "voltage input" type devices used for voltage-nerve conduction threshold (v-NCT) testing—under the assumption that they fall under a broader nerve conduction billing category. They do not. CMS explicitly addresses all of these device types as noncovered.

CMS Coverage Position Under NCD 270: What's Covered and What Isn't

To be unambiguous about the policy's current standing:

Nationally Covered Indications: None. CMS has designated no covered indications for sNCT testing.

Nationally Noncovered Indications: All uses of sNCT to diagnose sensory neuropathies or radiculopathies are noncovered for Medicare beneficiaries.

This is a blanket noncoverage determination. It doesn't matter whether the ordering provider is a neurologist, physiatrist, podiatrist, or pain specialist—the noncoverage applies universally across all Medicare claims for this service. There are no exceptions carved out for specific clinical scenarios, patient populations, or device types.

The 2026 modification doesn't reverse or soften this position. Billing teams should treat this update as a reaffirmation with the force of a current, reviewed NCD behind it.

Affected Codes

The policy document for NCD 270 does not list specific CPT or HCPCS codes. This is notable in its own right—it means there is no CMS-assigned billing code pathway for submitting sNCT claims under Medicare. Any claim submitted for sNCT services, regardless of the code used, falls under the noncoverage determination established by this NCD.

There are no covered codes, no conditionally covered codes, and no associated ICD-10 diagnosis codes that create a coverage pathway for sNCT testing under Medicare.

Practical implication: If your practice or facility has been billing sNCT services using unlisted neurological procedure codes or attempting to map sNCT tests to standard nerve conduction study codes, those claims are subject to denial and potential recoupment. This is an area where proactive auditing matters.

Prior Authorization and Medical Necessity Under NCD 270

Because sNCT is categorically noncovered, prior authorization is not applicable—there is no process to authorize a service that CMS has determined is not reasonable and necessary. Similarly, medical necessity documentation will not overcome this denial. Even the most detailed clinical documentation supporting the medical rationale for sNCT testing cannot override an NCD-level noncoverage determination.

This is worth communicating clearly to ordering providers, particularly those in neurology and pain management who may be accustomed to supporting coverage through robust documentation for other diagnostic tests.

What Your Billing Team Should Do