CMS Noncontact Normothermic Wound Therapy (NNWT) Coverage Policy: What Billing Teams Need to Know in 2026
The Centers for Medicare & Medicaid Services (CMS) has updated NCD 232, its National Coverage Determination for Noncontact Normothermic Wound Therapy (NNWT), with a modified policy effective March 12, 2026. The core coverage position remains firm: Medicare will not cover NNWT devices, citing insufficient scientific and clinical evidence that the technology is reasonable and necessary under §1862(a)(1)(A) of the Social Security Act. If your practice or facility is treating Medicare beneficiaries with chronic or acute wounds, this policy has direct revenue cycle implications you need to address now.
| Field | Detail |
|---|---|
| Payer | CMS (Medicare) |
| Policy | Noncontact Normothermic Wound Therapy (NNWT) |
| Policy Code | NCD 232 |
| Change Type | Modified |
| Effective Date | 2026-03-12 |
| Impact Level | Medium |
| Specialties Affected | Wound care, podiatry, general surgery, plastic surgery, home health, DME suppliers |
| Key Action | Ensure no Medicare claims are submitted for NNWT devices and that ABN processes are in place for patients who may request this therapy. |
What Is Noncontact Normothermic Wound Therapy and Why CMS Won't Cover It
NNWT is a durable medical equipment (DME) device designed to promote wound healing by warming the wound site to a predetermined temperature. The device consists of two primary components: a noncontact wound cover and a flexible, battery-powered infrared heating card inserted into that cover. The "noncontact" designation means the device does not directly touch the wound bed—the infrared heat is delivered through the cover.
The clinical theory behind NNWT is that localized warming increases blood flow and cellular activity, accelerating the healing process in chronic or hard-to-heal wounds. Despite that rationale, CMS reviewed the available scientific and clinical evidence and concluded it falls short of demonstrating that NNWT is reasonable and necessary for wound treatment.
This determination is governed by §1862(a)(1)(A) of the Social Security Act, the foundational Medicare provision that excludes payment for items and services not considered reasonable and necessary for the diagnosis or treatment of illness or injury. In plain terms: CMS has reviewed the evidence, found it insufficient, and codified non-coverage nationally through NCD 232.
CMS Medicare Coverage Position Under NCD 232
The coverage determination under NCD 232 is unambiguous. There is no covered indication for NNWT under Medicare. The policy does not establish any qualifying diagnoses, patient populations, or clinical scenarios under which NNWT would be reimbursable.
This is a national coverage determination, meaning it applies uniformly across all Medicare Administrative Contractors (MACs). A local coverage determination (LCD) cannot override an NCD. Providers cannot appeal to their MAC for a local exception to this policy.
The benefit category for NNWT is Durable Medical Equipment—meaning any claim for this device would route through DME billing channels. But under NCD 232, those claims will be denied. DME suppliers, home health agencies, wound care centers, and hospital outpatient departments all fall under the same prohibition.
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
Affected Codes
The policy does not list specific CPT, HCPCS, or ICD-10 codes. NCD 232 applies broadly to NNWT devices as a category, without enumerating individual billing codes for covered or non-covered services.
What this means for billing teams: The absence of listed codes does not create an opening to bill under an unlisted or alternative code. The non-coverage determination applies to the device and service itself. Billing for NNWT under a related HCPCS code for wound dressings, heat therapy, or DME would constitute incorrect coding and could expose your organization to claim denials, audits, or compliance risk.
If you are unsure how a specific device your facility uses is coded, consult your MAC directly or review the transmittal referenced in the policy: TN AB-02-025 (Program Memorandum Intermediaries/Carriers). That transmittal provides the claims processing instructions associated with this NCD.
Prior Authorization and Advance Beneficiary Notice (ABN) Considerations
Because NNWT is categorically non-covered by Medicare, prior authorization is not a pathway to reimbursement here—there is no authorization that would make this service payable. The non-coverage is statutory and evidence-based, not a utilization management decision.
However, the ABN (Advance Beneficiary Notice of Noncoverage) process is directly relevant. If a Medicare patient requests NNWT or a provider believes it would be clinically beneficial despite the NCD, the provider must issue a valid ABN before furnishing the service. This protects the organization's ability to bill the patient directly for a non-covered service, and it ensures the patient understands Medicare will not pay.
Failure to issue a proper ABN before providing a non-covered service means the provider cannot bill the patient—and absorbs the cost. For DME suppliers in particular, this is a real financial exposure point.
What Your Billing Team Should Do
| # | Action Item |
|---|---|
| 1 | Audit your encounter data immediately. Pull any claims from the past 12 months where NNWT devices were provided to Medicare beneficiaries. Identify whether those claims were submitted, how they were coded, and what the adjudication outcome was. Any paid claims for a non-covered service create a repayment risk. |
| 2 | Update your chargemaster and order entry systems by March 12, 2026. Ensure that NNWT devices are flagged as non-covered for Medicare payers at the point of order entry. This prevents inadvertent submission of non-covered claims and puts the ABN workflow in motion automatically when the service is ordered for a Medicare patient. |
| 3 | Refresh your ABN workflow for wound care encounters. Train front desk and clinical staff who work in wound care, podiatry, and surgical follow-up settings to recognize when NNWT is being considered and to trigger the ABN process before the service is delivered. Document the signed ABN in the patient record. |
| 4 | Brief your DME suppliers and referral partners. If your practice refers patients to external DME suppliers for wound care equipment, confirm those suppliers are aware of NCD 232 and are not submitting claims for NNWT under Medicare. Your referral creates a clinical connection—even if you don't bill for the device yourself, a pattern of inappropriate referrals can draw scrutiny. |
| 5 | Review the CMS transmittal AB-02-025. This transmittal contains the claims processing instructions tied to NCD 232. Your billing and compliance team should have this document on file and use it as the authoritative reference when questions arise about how to handle NNWT billing edge cases. |
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