By the Coding and Reimbursement Advisory Committee

Tonic motor activation (TOMAC), also known as bilateral peroneal nerve stimulation, is a therapeutic approach that delivers high-frequency electrical stimulation to the common peroneal nerves near the fibula in the lower legs. This stimulation activates the tibialis anterior muscle, resulting in sustained, low-intensity muscle contractions. These contractions are intended to mimic the physiological effects of voluntary lower-limb movements, such as walking or stretching, which are commonly associated with relief of restless legs syndrome (RLS) symptoms.

The proposed biological mechanism underlying TOMAC involves afferent sensory feedback. Electrical stimulation generates neural signals that are transmitted to the central nervous system, where they may help attenuate abnormal sensory processing that contributes to the urge to move the legs. By engaging neural circuits activated during natural movement, TOMAC may modulate both spinal and supraspinal pathways implicated in RLS.

Documentation requirements

To support medical necessity and appropriate use, documentation for TOMAC should include the following elements:

  1. Confirmed RLS diagnosis and severity. Document primary RLS, symptom severity, and, ideally, a validated severity score. One current policy requires an International Restless Legs Syndrome (IRLS) Rating Scale score of 15 or greater for moderate to severe disease.
  2. Refractory status. Document that the patient is refractory to medications or unable to tolerate or has contraindications for them. Payer criteria commonly look for failure or intolerance of one or more classes, such as gabapentin, dopamine agonists, and opioids, depending on the plan.
  3. Reversible or exacerbating factors addressed. This is a major utilization management point. Policies commonly require documentation that exacerbating factors have been assessed and addressed, such as iron deficiency, alcohol or caffeine use, antidopaminergic drugs, untreated obstructive sleep apnea (OSA), or other sleep disorder.
  4. Symptom pattern and anatomic fit. Document that symptoms occur predominantly in the lower legs or feet, usually in the evening or at night, and with enough frequency to justify therapy. One current policy uses two or more nights per week.
  5. Contraindications and safety screening. Document the absence of contraindications such as epilepsy or seizure disorder, active implanted electronic devices, metal implant at the therapy site, allergy to device materials or adhesives, cellulitis, open sores, or injury at the application site. Also document that the patient was instructed not to use the device while driving or operating machinery.
  6. Prescription, fitting, and training. Because TOMAC is prescription-only and clinic-programmed, retain the prescription, fitting and calibration record, patient instructions, and any manufacturer intake forms or checklists used to support dispensing and prior authorization.
  7. Response for continuation. For ongoing coverage, document a measurable response. One current policy requires documentation that RLS symptoms decreased with consistent use.

Code set

For the TOMAC system, the Centers for Medicare & Medicaid Services (CMS) established two dedicated Healthcare Common Procedure Coding System (HCPCS) codes, effective Oct. 1, 2024:

  • HCPCS E0743 – Wearable electrical stimulator device for tonic motor activation therapy. This code is used to bill the TOMAC device.
  • HCPCS A4544 – Supplies for use with tonic motor activation therapy. This code is used to bill associated disposable or replenishable supplies required to operate the TOMAC system.

Important coding distinctions

  • No Current Procedural Terminology (CPT) codes are used to report TOMAC therapy, as the treatment does not involve a billable physician procedure, implantation, or percutaneous nerve intervention. Billing is handled under the durable medical equipment (DME) benefit using HCPCS Level II codes.
  • Peripheral nerve stimulation CPT codes (e.g., 64555, 64561, 64566) are not appropriate for TOMAC, as these codes describe invasive or percutaneous neurostimulation procedures that do not reflect the noninvasive, wearable nature of TOMAC therapy.

Billing pitfalls

Most challenges in billing TOMAC are operational rather than conceptual, and each pitfall builds on the previous one, increasing the risk of denial or confusion.

  1. Use the proper code family. Do not treat TOMAC as a generic office-based electrical stimulation modality. The verified product-specific codes are E0743 and A4544. Payer policies also list generic electrical stimulation CPT or HCPCS codes such as 97014, 97032, and G0283, but those are not TOMAC device codes and create obvious denial risk if used as substitutes.
  2. Recognize that code E0743 is billed per unit. CMS intentionally designated E0743 as applying to each unit, not as a bilateral system. Billing requires understanding that each unit represents one device, so two units are needed for both legs. Staff must also understand replacement logic and not assume the code descriptor includes both legs automatically.
  3. Account for DME and capped rental requirements. CMS classified TOMAC as DME and priced it as a capped rental, meaning it should not be billed as a one-time in-office supply or an implanted neurostimulator pathway.
  4. Ensure sufficient documentation. Denials are likely if the chart does not clearly show persistent symptoms despite medication, a failed or intolerant treatment history, and that reversible drivers like iron deficiency or untreated OSA were addressed.
  5. Address coverage variability across payers. Coverage is inconsistent. Some plans require prior authorization or have unique medical necessity pathways, while others still consider TOMAC to be investigational. Always review plan-specific policies and prepare for appeals.
  6. Consider contraindications or comorbidities. Payers may deny coverage, or clinicians may defer therapy, when there is untreated OSA or another sleep disorder, peripheral neuropathy of the lower extremities, pregnancy, or device or site contraindications.

Use case example

Patient: A 66-year-old Medicare beneficiary with a 10-year history of restless legs syndrome, hypertension, Type 2 diabetes, and chronic sleep disruption.

Clinical question: Is TOMAC an appropriate treatment option for persistent RLS symptoms despite prior medication trials?

Sleep physician activities:

  • Review of RLS history, symptom severity, prior pharmacologic treatments, and reasons for limited response or intolerance
  • Assessment using the IRLS Rating Scale, confirming moderate to severe symptoms
  • Evaluation of exclusionary conditions and contraindications
  • Determination that TOMAC is clinically appropriate as a nonpharmacologic treatment option
  • Prescription of TOMAC therapy and documentation supporting medical necessity
  • Patient education regarding device use and expectations
  • Written clinical documentation completed in the electronic health record

Total time: Not time-based; therapy provided as a DME benefit

Appropriate codes:

  • E0743 – Wearable electrical stimulator device for tonic motor activation therapy
  • A4544 – Supplies for use with tonic motor activation therapy

Summary: The role of TOMAC in treating RLS

TOMAC represents an important medication-free option in the management of RLS, particularly for patients with persistent symptoms despite prior treatment or those unable to tolerate medication therapy. By replicating the physiological effects of voluntary movement through targeted peroneal nerve stimulation, TOMAC addresses a core feature of the RLS disease process while avoiding systemic drug exposure. As payer coverage expands and coding pathways become more defined, appropriate patient selection, thorough clinical documentation, and accurate DME billing will be essential to ensure compliant access to this emerging therapy in sleep medicine practice.

This article appeared in volume 11, issue 3 of Montage magazine.