Electrical Stimulation (ES) and Electromagnetic Therapy for the Treatment of Wounds — NCD 131 | CMS Coverage Update

TL;DR: The Centers for Medicare & Medicaid Services modified NCD 131, the national coverage determination governing electrical stimulation and electromagnetic therapy for wound treatment, effective March 7, 2026. Here's what billing teams need to know.

CMS wound therapy billing has not fundamentally changed in approach, but the NCD 131 Medicare documentation requirements are stringent — and claims die fast when the 30-day standard care threshold isn't clearly established in the record. This policy covers ES and electromagnetic therapy as adjunctive wound treatments across physician services, outpatient physical therapy, and incident-to services. No specific CPT or HCPCS codes are listed in the policy document itself. Your billing team will need to verify applicable codes with your Medicare Administrative Contractor.

Quick-Reference Table

CMS Electrical Stimulation and Electromagnetic Therapy Coverage Criteria and Medical Necessity Requirements 2026

The CMS electrical stimulation and electromagnetic therapy coverage policy under NCD 131 is narrowly defined. These are adjunctive therapies only. You cannot bill them as a first-line treatment.

Medicare covers ES and electromagnetic therapy for four wound types: chronic Stage III or Stage IV pressure ulcers, arterial ulcers, diabetic ulcers, and venous stasis ulcers. "Chronic" has a specific definition here — the wound must have failed to heal within 30 days of occurrence.

Coverage has a second gate beyond wound type. Standard wound therapy must have been tried for at least 30 days with no measurable signs of improved healing before ES or electromagnetic therapy can be billed. This 30-day clock can start while the wound is acute, which gives you some flexibility — but the period must be documented.

Standard wound care under this coverage policy means all of the following: nutritional optimization, debridement to remove devitalized tissue, moist wound bed maintenance with appropriate dressings, and infection treatment. For specific wound types, the bar goes higher. Pressure ulcer patients need documented repositioning, usually every two hours. Diabetic ulcer patients need documented offloading and glucose control. Arterial ulcer patients need documented circulation management. Venous ulcer patients need a documented compression system.

Medical necessity for continued treatment carries its own threshold. Measurable healing must be demonstrated within every 30-day treatment period. Measurable healing means a documented decrease in wound size (surface area or volume), a decrease in exudate, or a decrease in necrotic tissue. If you can't show one of those three things in a 30-day window, coverage stops.

Treatment must also stop when the wound reaches 100% epithelialized wound bed. Billing past that point is a denial waiting to happen.

On the supervision side: ES and electromagnetic therapy can only be billed when performed by a physician, a physical therapist, or incident to a physician service. The treating practitioner must evaluate the wound at each session and contact the treating physician if the wound worsens. The treating physician must evaluate the wound at least monthly regardless of who is performing the therapy. That monthly physician evaluation is a hard documentation requirement, not a recommendation.

There are no prior authorization requirements spelled out in NCD 131 itself, but your Medicare Administrative Contractor may have additional local coverage determination requirements layered on top. Check with your MAC before assuming the national coverage determination is the whole story.

CMS Electrical Stimulation and Electromagnetic Therapy Exclusions and Non-Covered Indications

Three clear non-covered indications appear in NCD 131, and each one is a claim denial risk if your documentation doesn't address it.

First: ES and electromagnetic therapy as initial treatment. The policy is explicit. These are not covered as a first-line modality. If the claim doesn't show a 30-day standard wound care trial with documented failure to heal, the claim has no medical necessity basis under this coverage policy.

Second: Continued treatment without documented healing progress. This one catches practices off guard. You don't just establish medical necessity at the start and forget it. Every 30-day period of treatment requires documented measurable healing. Miss a cycle of documentation, and continued treatment loses its coverage basis retroactively.

Third: Unsupervised use. CMS found unsupervised ES and electromagnetic therapy for wound treatment not to be medically reasonable and necessary. Home use by a patient without qualified supervision does not meet this coverage policy. If your patients are taking equipment home and self-treating, reimbursement is off the table under NCD 131.

All other uses of ES and electromagnetic therapy for wound treatment that aren't specified in NCD 131 fall to Medicare Administrative Contractor discretion. That means local coverage determination rules apply — and those vary by MAC jurisdiction. Don't assume national coverage extends to off-label applications.

Coverage Indications at a Glance

CMS Wound Therapy Billing Guidelines and Action Items 2026

This is where the policy's complexity shows up in revenue cycle work. NCD 131 is not complicated to read — but it creates multiple documentation checkpoints that billing teams often don't control directly. Here's what to do before and after the March 7, 2026 effective date.

CPT, HCPCS, and ICD-10 Codes for Electrical Stimulation and Electromagnetic Therapy Under NCD 131

NCD 131 does not list specific CPT, HCPCS Level II, or ICD-10-CM codes within the policy document. This is a meaningful gap for electrical stimulation and electromagnetic therapy billing.

Contact your Medicare Administrative Contractor directly to get the correct billing codes for your jurisdiction. Ask specifically whether a local coverage determination exists for ES or electromagnetic therapy for wound treatment — many MACs have issued LCDs that include specific code lists, documentation requirements, and coverage criteria that supplement NCD 131.

When you have confirmed codes from your MAC, map them against the covered indications table above and build your charge capture logic accordingly. Don't estimate or borrow code lists from other policies. The covered wound types and therapy types here are specific enough that using the wrong code will produce denials even when the clinical documentation is solid.