CMS Updates NCD 309: What Billing Teams Need to Know About Aprepitant Coverage for Chemotherapy-Induced Nausea

The Centers for Medicare & Medicaid Services (CMS) has modified National Coverage Determination (NCD) 309, which governs Medicare coverage of aprepitant (Emend®) for chemotherapy-induced nausea and vomiting (CINV). This update—effective March 12, 2026—clarifies the covered drug combinations, eligible chemotherapy agents, and the boundaries of what Medicare will and will not reimburse for this oral antiemetic regimen. For oncology billing teams and revenue cycle managers, getting this right is critical: CINV management is a high-frequency billing area where coverage gaps can generate significant claim denials.

What NCD 309 Covers: CMS Aprepitant Coverage for CINV

Aprepitant is the first FDA-approved neurokinin-1 (NK1) receptor antagonist indicated to prevent CINV. CMS covers it under the Oral Antiemetic Drugs benefit category—but only under specific clinical conditions. The policy is structured around two coverage periods with distinct eligible drug lists, and billing teams must understand both.

Under the original coverage determination (effective April 4, 2005, through May 28, 2013), aprepitant was covered only when patients were receiving one or more of these specific chemotherapy agents:

• Carmustine
• Cisplatin
• Cyclophosphamide
• Dacarbazine
• Mechlorethamine
• Streptozocin
• Doxorubicin
• Epirubicin
• Lomustine

Effective May 29, 2013—and continuing under this updated policy—coverage expanded significantly. The covered regimen is now applicable to a broader list of anticancer agents, administered singularly or in combination.

Expanded Eligible Chemotherapy Agents Under NCD 309 (May 29, 2013 Forward)

The current covered chemotherapy agent list is substantially longer than the original. Medicare will cover aprepitant as part of the approved three-drug regimen when any of the following agents are being administered:

This list reflects agents CMS has cross-referenced against guidelines from at least two of three major oncology bodies: the National Comprehensive Cancer Network (NCCN), the American Society of Clinical Oncology (ASCO), and the European Society of Medical Oncology (ESMO)/Multinational Association of Supportive Care in Cancer (MASCC). An agent qualifies as highly or moderately emetogenic when designated as such in at least two of those three guideline sources.

Medical Necessity Requirements: The Three-Drug Regimen

Coverage under NCD 309 isn't just about which chemotherapy agent a patient is receiving—it's also about how aprepitant is prescribed. CMS has established that the evidence supports coverage only for a specific oral three-drug combination:

All three drugs must be administered together. Aprepitant alone does not meet medical necessity criteria under this NCD—CMS explicitly determined that the evidence is insufficient to support aprepitant as a standalone antiemetic.

The timing requirement is equally important for documentation: the three-drug regimen must be administered immediately before and within 48 hours after the administration of the covered chemotherapy agents. If your documentation doesn't reflect this timing, expect denials.

What CMS Does Not Cover Under NCD 309

CMS has drawn a clear line: aprepitant cannot function as a standalone antiemetic for CINV. Any claim for aprepitant without the concurrent three-drug regimen—or outside the timing window—will not meet medical necessity requirements under this policy.

Additionally, coverage applies only when the patient is receiving one of the listed chemotherapy agents. If the treating oncologist uses aprepitant for a chemotherapy regimen that does not appear on the covered agent list, the claim will not be supported by this NCD. Teams billing for newer or off-label chemotherapy regimens should verify whether a Local Coverage Determination (LCD) applies before submitting.

How CMS Defines "Highly Emetogenic" and "Moderately Emetogenic" Chemotherapy

One of the more operationally significant clarifications in NCD 309 is how CMS defines emetogenicity tiers. Rather than relying on a single guideline source, CMS requires agreement across at least two of three recognized oncology guidelines (NCCN, ASCO, or ESMO/MASCC). The valid combinations are:

• NCCN + ASCO
• NCCN + ESMO/MASCC
• ASCO + ESMO/MASCC

This cross-guideline standard affects how medical necessity is established and documented. When building your clinical documentation workflow, ensure that the treating oncologist's notes reflect the emetogenic classification consistent with these guidelines—not just internal protocol references.

Affected Codes

This policy does not list specific CPT or HCPCS codes in its code table. Billing teams should reference current HCPCS coding references for aprepitant (Emend®) and the associated 5HT3 antagonist and dexamethasone drugs, as applicable to the claim context. Consult your payer fee schedules and the CMS HCPCS quarterly update files for the current applicable drug codes.

For diagnosis coding, claims should reflect the documented CINV diagnosis in support of medical necessity. Standard ICD-10-CM coding guidance for nausea and vomiting associated with antineoplastic chemotherapy applies; no specific diagnosis codes are enumerated in this NCD.

What Your Billing Team Should Do