TL;DR: The Centers for Medicare & Medicaid Services modified NCD 155, its sublingual antigen coverage policy, with an effective date of March 7, 2026. Medicare does not cover antigens administered sublingually — only injection-based administration is covered. Here's what your billing team needs to know.
This policy has been on the books since November 17, 1996, but the March 7, 2026 modification to NCD 155 in the CMS system makes it worth revisiting. If your practice or billing team handles allergy therapy claims, this coverage policy draws a hard line: sublingual antigen administration gets denied. Injection-based antigen administration is covered. There is no gray area, no prior authorization pathway that unlocks sublingual coverage, and no medical necessity argument that overcomes this exclusion.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS / Medicare |
| Policy | Antigens Prepared for Sublingual Administration |
| Policy Code | NCD 155 |
| Change Type | Modified |
| Effective Date | 2026-03-07 |
| Impact Level | Medium |
| Specialties Affected | Allergy/Immunology, ENT, Primary Care (allergy services) |
| Key Action | Audit your charge capture and superbill to confirm no sublingual antigen claims are being submitted to Medicare |
CMS Sublingual Antigen Coverage Criteria and Medical Necessity Requirements 2026
NCD 155 is the National Coverage Determination governing Medicare coverage of antigens for allergy immunotherapy. The rule is simple: Medicare covers antigens only when administered by injection.
Sublingual immunotherapy — drops placed under the patient's tongue — does not meet Medicare's medical necessity standard under this policy. CMS has determined that sublingual antigen therapy has not been proven safe and effective. That finding controls coverage, and it has since November 17, 1996.
No medical necessity documentation changes that outcome. You cannot write a stronger letter of medical necessity, get a physician attestation, or submit additional clinical records that will flip a sublingual antigen claim from denied to paid under Medicare. The coverage policy is categorical.
Whether sublingual antigen therapy is effective is a separate clinical debate. For Medicare billing purposes, the answer from CMS is settled. If your clinicians offer sublingual immunotherapy to Medicare patients, those patients are paying out of pocket — full stop.
This is not a gray-zone policy where prior authorization might open a door. There is no prior authorization pathway for sublingual antigen administration under Medicare. Prior auth is irrelevant here because the service is not covered at all. If a patient or clinician asks whether prior auth would help, the answer is no.
The CMS sublingual antigen coverage policy applies to antigens provided to patients on or after November 17, 1996. The 2026 modification to NCD 155 in the CMS system does not change that underlying coverage rule — but it refreshes the policy's standing as the governing NCD, and it's your signal to verify your billing workflows are aligned.
CMS Sublingual Antigen Exclusions and Non-Covered Indications
The exclusion here is specific and narrow: antigens prepared for sublingual administration are not covered under Medicare.
CMS's stated reason is clinical. Sublingual allergy therapy has not been proven safe and effective. That's the exact language in the policy. This is a non-coverage determination based on insufficient clinical evidence — the same framework CMS uses for other services it categorizes as unproven or investigational.
This matters because the exclusion is not diagnosis-specific. It doesn't matter whether the patient has allergic rhinitis, asthma, food allergies, or any other condition driving the allergy therapy. If the administration route is sublingual, Medicare won't pay. The exclusion is defined entirely by how the antigen is delivered, not why.
Some practices assume that if a service is clinically defensible, Medicare will cover it with enough documentation. That's not how NCD-level exclusions work. An NCD exclusion overrides local coverage determinations and MAC discretion. No Medicare Administrative Contractor can override NCD 155 to cover sublingual antigens — it's set at the national level.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Antigens administered by injection | Covered | No specific codes listed in NCD 155 | Standard allergy immunotherapy; must be injection-based |
| Antigens administered sublingually (drops under tongue) | Not Covered | No specific codes listed in NCD 155 | Excluded for all diagnoses; no prior authorization pathway; patient financial responsibility if service provided |
CMS Sublingual Antigen Billing Guidelines and Action Items 2026
The policy is clear. Your billing team's job is to make sure your workflows match it. Here are the steps to take now, before or after the March 7, 2026 effective date.
| # | Action Item |
|---|---|
| 1 | Audit your charge capture for any antigen administration codes. Pull claims from the last 12 months where antigen therapy was billed to Medicare. Flag any that involved sublingual administration. If those claims were paid, you may have a repayment exposure. Talk to your compliance officer before the effective date if you find anything. |
| 2 | Update your superbill and charge capture to block sublingual antigen codes from routing to Medicare. Your billing team should not be able to accidentally submit a sublingual antigen claim to Medicare. Build that guardrail in now. |
| 3 | Brief your clinical staff on the coverage rule. Clinicians offering sublingual immunotherapy need to know that Medicare patients will not have coverage. This is a patient financial counseling issue as much as a billing issue. Patients should know before the service, not after the denial. |
| 4 | Issue an Advance Beneficiary Notice of Noncoverage (ABN) for sublingual antigen services. If a Medicare patient elects to receive sublingual antigen therapy — knowing Medicare won't cover it — you need a signed ABN on file before delivering the service. Without it, you can't bill the patient. This is where the claim denial risk turns into a revenue problem. |
| 5 | Confirm that your reimbursement tracking separates injection-based and sublingual antigen services. If your practice provides both, your reporting needs to show which revenue comes from covered injection-based therapy versus self-pay sublingual therapy. Mixing those in your reimbursement tracking creates compliance risk. |
| 6 | Do not submit appeals for denied sublingual antigen claims. This is not a coverage determination where an appeal is likely to succeed. Spending staff time on appeals for NCD-excluded services is a waste of your revenue cycle resources. Redirect that time to ensuring ABNs are in place. |
If you're billing for allergy immunotherapy across a multi-specialty group or a high-volume ENT or allergy practice, loop in your compliance officer to review your current sublingual antigen billing practices against this policy before the effective date.
| 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 |
CPT, HCPCS, and ICD-10 Codes for Sublingual Antigens Under NCD 155
A Note on Codes
NCD 155 does not list specific CPT or HCPCS codes. The policy defines coverage based on the administration route — sublingual versus injection — rather than by specific procedure codes.
This is actually a billing complication worth flagging. Because the policy is route-dependent rather than code-dependent, claim denials for sublingual antigen therapy may not be caught by payer edits tied to specific codes. The denial risk lives in documentation and clinical notes, not just code selection.
Your billing team should work with your clinical documentation team to ensure that the administration route is clearly captured in the medical record. If a payer audits antigen claims, the administration route in the clinical note is what determines whether the claim was appropriate.
There are no CPT, HCPCS, or ICD-10 codes listed in NCD 155 to include in a code table. Do not assume that any specific allergy or antigen code is automatically excluded or automatically covered based on this policy alone — the coverage determination turns on documentation of how the antigen was administered.
If you want to know which allergy immunotherapy codes your Medicare Administrative Contractor addresses in local coverage determinations, check your MAC's LCD database. Local Coverage Determinations from your MAC may provide more specific code-level guidance that supplements NCD 155.
Get the Full Picture
Track this policy across versions, search 1,500+ policies by CPT code, and get real-time alerts when any payer changes coverage.