CMS NCD 4 Update: Heat Treatment and Diathermy/Ultrasound Coverage for Pulmonary Conditions

CMS has issued a modification to National Coverage Determination (NCD) 4, addressing heat treatment—specifically diathermy and ultrasound—when billed for pulmonary conditions. The updated policy reinforces CMS's longstanding position that these modalities are non-covered for respiratory diagnoses including asthma and bronchitis. Billing teams treating pulmonary patients or working with physical medicine providers need to understand what this modification means for claims submitted to Medicare.

What CMS NCD 4 Actually Says About Diathermy and Ultrasound for Pulmonary Conditions

The Centers for Medicare & Medicaid Services (CMS) is explicit in this policy: there is no physiological rationale and no valid scientific documentation supporting the effectiveness of diathermy or ultrasound heat treatments for asthma, bronchitis, or any other pulmonary condition.

Because CMS cannot establish that these treatments are reasonable and necessary under section 1862(a)(1) of the Social Security Act, they are non-covered when applied to pulmonary indications. This is not a gray area. The language is absolute.

The benefit category at issue is Physicians' Services, which means this determination applies across the board to physician-administered or physician-ordered heat treatment modalities when the clinical intent is treating a pulmonary condition.

Why This Modification Matters Even When Coverage Hasn't Changed

Policy modifications don't always flip a covered service to non-covered—or vice versa. Sometimes they clarify language, update cross-references, or align an older NCD with current CMS guidance. That's the case here.

The core non-coverage position on diathermy and ultrasound for pulmonary conditions has been CMS's stance for decades. What matters for your billing team is that this policy was actively revisited and reaffirmed. When CMS modifies a policy—even to maintain the same coverage status—it signals that the policy is under active review and that the underlying rationale has been re-examined.

For revenue cycle teams, a modified status is also a compliance trigger. If your practice or facility has any processes, templates, or order sets that could result in these services being billed to Medicare with a pulmonary diagnosis code, this is the moment to audit them.

Understanding the Medical Necessity Standard Under Section 1862(a)(1)

CMS's non-coverage determination here is rooted in the "reasonable and necessary" standard, which is the foundational test for Medicare coverage. Under section 1862(a)(1) of the Act, Medicare will not pay for items or services that are not reasonable and necessary for the diagnosis or treatment of illness or injury.

For a treatment to meet this standard, CMS generally requires some combination of the following: established physiological rationale, peer-reviewed evidence of clinical effectiveness, and general acceptance in the medical community. Diathermy and ultrasound heat treatments for pulmonary conditions fail on all counts according to this NCD—CMS found neither a physiological basis nor valid scientific evidence to support their use in this context.

This is distinct from whether these same modalities might be covered for musculoskeletal or other non-pulmonary indications. Diathermy and therapeutic ultrasound do have covered applications in other clinical contexts. The non-coverage here is specific to pulmonary conditions. Context—and the diagnosis code attached to the claim—is everything.

The Risk of Cross-Specialty Billing Errors

One area where billing teams can get into trouble: physical medicine or rehabilitation providers treating patients who also carry pulmonary diagnoses. If a patient is being seen for a musculoskeletal complaint and also has a documented history of COPD, asthma, or bronchitis, care must be taken that the diagnosis codes on any diathermy or ultrasound heat treatment claim reflect the actual condition being treated—not the pulmonary comorbidity.

This is not theoretical. Medicare claims are reviewed for diagnosis-to-procedure code alignment. Submitting heat treatment with a pulmonary primary diagnosis, even inadvertently, creates a compliance exposure. That includes routine claim scrubbing, but it also includes post-payment audit risk.

Practices using electronic health records that auto-populate problem list diagnoses onto therapy claims need to verify that their billing workflows are set up to capture the treating diagnosis—not just the patient's full problem list.

Affected Codes

This policy does not list specific CPT or HCPCS codes. CMS's NCD 4 addresses heat treatment including diathermy and ultrasound as service categories without assigning specific procedure code designations within the policy document itself.

For billing guidance on the specific procedure codes used to report diathermy or therapeutic ultrasound in your practice, refer to your Medicare Administrative Contractor (MAC) for local claims processing instructions, and cross-reference NCD Manual section 150.5 as directed in the policy.

Related ICD-10 Diagnosis Codes

No ICD-10 codes are specified in the policy document. However, the following diagnosis categories are explicitly named as non-covered indications when paired with heat treatment modalities—your team should flag claims where these conditions appear as the primary indication for treatment:

When reviewing claims internally, focus on ICD-10-CM codes in the J00–J99 range (Diseases of the Respiratory System) appearing as the primary diagnosis on heat treatment claims submitted to Medicare.

What Your Billing Team Should Do