CMS NCD 321 Modified: What the Nebulized Beta Adrenergic Agonist Policy Change Means for Your MAC

The Centers for Medicare & Medicaid Services has modified NCD 321, its national coverage determination for nebulized beta adrenergic agonist therapy for lung diseases. The key operational takeaway: CMS is not establishing national coverage criteria for this therapy—meaning your local Medicare Administrative Contractor (MAC) holds the decision-making authority on coverage, medical necessity, and reimbursement. For billing teams managing COPD and asthma patients on nebulized bronchodilator therapy, that distinction drives everything from documentation strategy to denial appeals.

What CMS NCD 321 Actually Says About Nebulized Beta Agonist Coverage

CMS reviewed the available medical evidence for nebulized beta adrenergic agonist therapy—including both racemic albuterol and levalbuterol—and concluded that a national coverage determination is not appropriate at this time. That language comes directly from Section D of the policy, which governs how coverage decisions are handled when CMS declines to set a uniform national rule.

Under Section 1862(a)(1)(A) of the Social Security Act, decisions about whether nebulized beta agonist therapy is reasonable and necessary for a specific Medicare patient are delegated to local Medicare Administrative Contractors. MACs can handle these through a formal local coverage determination (LCD) process or through case-by-case adjudication.

This structure means there is no single national answer to "does Medicare cover nebulized albuterol or levalbuterol for COPD?" The answer depends entirely on where your patient receives care and which MAC jurisdiction covers their claims.

Racemic Albuterol vs. Levalbuterol: Why the Distinction Matters for Billing

NCD 321 specifically calls out both racemic albuterol and levalbuterol, the (R) enantiomer of racemic albuterol, as agents used in nebulized beta adrenergic agonist therapy. The policy notes that levalbuterol has been used in specific patient populations more recently, and flags concerns about appropriate use—which is part of why CMS has kept oversight at the MAC level rather than setting national rules.

From a billing standpoint, these two agents are not interchangeable from a coverage perspective. Your MAC's LCD or adjudication standards may treat them differently, apply different medical necessity thresholds, or require distinct documentation to support the choice of one over the other. If your clinical staff is prescribing levalbuterol where racemic albuterol would also be clinically appropriate, your documentation needs to explicitly justify that clinical decision.

The DME Benefit Category: How Nebulized Therapy Gets Billed Under Medicare

NCD 321 falls under the Durable Medical Equipment benefit category. That classification matters for how claims route and who bills them. In most cases, the nebulizer equipment itself—and potentially the drug supply—is billed by a DME supplier, not the treating physician's practice.

However, the prescribing provider's documentation directly determines whether the DME supplier can establish medical necessity and get paid. If your practice is writing orders for home nebulizer therapy, your clinical notes, diagnosis coding, and treatment rationale are the foundation of the DME claim downstream. A weak order or thin documentation creates denial risk that your patient and your referring DME supplier will both feel.

Why MAC Jurisdiction Is the Actual Coverage Rule Here

When CMS declines to issue a national coverage determination and defers to local adjudication, billing teams have to do more work—not less. You cannot rely on a single national policy document to validate your claims. Instead, you need to know:

• Which MAC jurisdiction covers your facility or DME supplier
• Whether that MAC has a published LCD specifically addressing nebulized beta agonist therapy
• What diagnosis codes, clinical documentation criteria, and prior authorization requirements that LCD specifies
• Whether your MAC is handling claims under a formal LCD or case-by-case adjudication

MACs can and do update their LCDs independently of CMS national policy changes. NCD 321 being modified at the national level is a signal to check whether your MAC has also updated its local guidance.

Affected Codes

This policy does not list specific CPT or HCPCS codes. Because CMS has deferred coverage decisions to local MAC adjudication, applicable billing codes—including HCPCS codes for nebulized drug supply and DME equipment—will be governed by your MAC's local coverage determination or adjudication standards rather than by NCD 321 directly.

Contact your MAC or review their published LCD for the specific codes they recognize for nebulized beta adrenergic agonist therapy and related DME equipment.

What Your Billing Team Should Do