Transcutaneous Devices Face Array of Classification Codes

by Victor Pikov, contributing editor

December 2025 issue

Transcutaneous electrical stimulation devices can be subdivided into three major categories: TENS, tVNS, and cranial electrotherapy stimulators, based on electrode placement on the body. TENS devices are used below the neck, tVNS devices are applied at the neck or ear, and CES devices are used above the neck. Although these devices are functionally similar, their FDA classifications differ significantly.

All TENS devices intended for pain treatment are classified by the FDA under a single regulation number (882.5890) and are regulated as Class II, requiring 510(k) clearance. The FDA’s 510(k) database includes more than 200 TENS devices cleared since 2020. These devices fall into four sub-categories: 120 are over-the-counter TENS devices for general pain (code NUH), 31 over-the-counter TENS devices for arthritis pain (code NUH), 50 prescription TENS devices for pain (code GZJ), and nine prescription TENS devices for pain that use continuous sine waves in the kHz range to generate interferential current (code LIF).

In addition to pain indications, TENS devices used to treat fibromyalgia, restless legs syndrome, and urinary incontinence are also regulated as Class II. For fibromyalgia (code QSQ), a single de novo 510(k) clearance was granted to NeuroMetrix, which was recently acquired by electroCore. For restless leg syndrome (code QWD), a single de novo 510(k) clearance was issued to the U.S. firm Noctrix Health. TENS devices for urinary incontinence (code NAM) are marketed by Avation Medical and Exodus Innovations, as discussed in an earlier article.

tVNS devices are placed on the neck to stimulate the cervical vagus or on the ear to stimulate the auricular branch of the vagus. All tVNS devices are regulated as Class-II, similar to TENS devices. Since 2020, the FDA has issued three 510(k) clearances for cervical tVNS, all for electroCore’s gammaCore devices for treating headache/migraine (codes PKR and QAK). During the same period, the FDA has issued 11 510(k) clearances for auricular tVNS. These include six clearances for opioid withdrawal (code PZR) from three U.S. companies Spark Biomedical, Net Recovery, and DyAnsys and five clearances for pain associated with irritable bowel syndrome (code QHH) from three U.S. companies NeurAxis, Transtimulation Research, and DyAnsys.

FDA classification of CES devices is considerably more complex and ranges from Class I to Class III, depending on the indication. Among the 34 CES devices that entered the U.S. market since 2020, one device for the treatment of obesity (code SFW) is classified as Class-I, and one for device the treatment of depression (code JXK) is classified as ClassIII. The remaining 32 devices are under ClassII and include: two devices for insomnia and stress (code QJQ), 26 devices for headaches (including migraine) (codes PCC and QGT), and four devices for attention deficit hyperactivity disorder (code QGL).

The U.K.-based company Neurovalens manufactures the only CES device for the treatment of obesity, which was allowed by the FDA in October 2025 without requiring 510(k) clearance. The same company also produces both CES devices cleared for the treatment of insomnia and stress. All Neurovalens devices stimulate the vestibular nerve using electrodes placed behind the ears and deliver tDCS with a pulse duration of two seconds and a current of up to 1 mA for 30 minutes per session.

Several companies have received 510(k) clearance for CES devices used to treat headache and migraine using AC pulses (code PCC), including Korea-based Nu Eyne, Belgium-based Cefaly Technology, and Israel-based Neurolief. In addition, Israel-based Theranica has multiple 510(k)-cleared CES devices for headache/migraine using tDCS (code QGT). Nu Eyne, Korea-based Bistos, and NeuroSigma have received 510(k) clearance for CES devices used to treat ADHD.

The Sweden-based company Flow Neuroscience manufactures the only CES device approved for the treatment of depression. Before receiving PMA approval in December 2025, the device had been approved for use in the EU and the UK since 2019. It uses scalp electrodes positioned over the prefrontal cortex and delivers tDCS at 2 mA for 30 min per session.

Historically, all tDCS CES devices for insomnia, stress, and depression were regulated as Class III devices. In 2019, the FDA re-classified CES devices for insomnia and stress as Class II, based on clinical evidence supporting their efficacy. At the same time, the FDA considered re-classifying CES devices for depression as Class II but ultimately declined. This decision was based on review of six randomized controlled trials, five of which showed no statistically significant difference in depression outcomes between patients treated with active CES and those receiving placebo treatment. As additional clinical evidence becomes available, it is possible that CES devices for treatment of depression may eventually be reclassified as Class II.

In an upcoming article, we will examine the equally complex topic of reimbursement levels for transcutaneous electrical nerve stimulation devices, which also vary by indication and depend on the strength of supporting clinical evidence.