Quick answer
J2357Q5154
What Medicare pays for Omalizumab (Xolair) (2026 Q2)
Once a claim carries a covered diagnosis, Medicare Part B reimburses the drug at the ASP + 6% payment limit. Current allowed amounts per billing unit:
| HCPCS | Description | Per unit | Allowed (ASP + 6%) |
|---|---|---|---|
| J2357 | Omalizumab injection | 5 mg | $41.823 |
Source: CMS ASP Drug Pricing File, 2026 Q2. Payment = ASP + 6% per unit; multiply by units billed (watch JZ/JW wastage). Your patient's share is typically 20% after the deductible. Estimate the full cost & patient out-of-pocket →
Omalizumab (Xolair) is a physician-administered biologic billed under Medicare Part B (not the Part D pharmacy benefit). Under Part B, Medicare pays the practice for the drug (HCPCS J2357) plus its administration — but only when the claim's diagnosis (ICD-10) code supports medical necessity. Each MAC publishes the specific covered diagnoses in a Billing & Coding Article; a claim with a diagnosis outside that list is typically denied as not medically necessary (CO-50).
Covered ICD-10 diagnoses for Omalizumab (Xolair)
The 17 codes below are the diagnoses National Government Services, Inc. accepts for J2357 under Article A52448, grouped exactly as CMS groups them and organized by condition category for scanning. Use the filter in each group to find a specific code or condition.
Group 1 — 17 covered diagnoses
Diseases of the respiratory system (7)
| ICD-10 | Covered diagnosis |
|---|---|
| J33.0 | Polyp of nasal cavity |
| J45.40 | Moderate persistent asthma, uncomplicated |
| J45.41 | Moderate persistent asthma with (acute) exacerbation |
| J45.42 | Moderate persistent asthma with status asthmaticus |
| J45.50 | Severe persistent asthma, uncomplicated |
| J45.51 | Severe persistent asthma with (acute) exacerbation |
| J45.52 | Severe persistent asthma with status asthmaticus |
Diseases of the skin & subcutaneous tissue (4)
| ICD-10 | Covered diagnosis |
|---|---|
| L50.1 | Idiopathic urticaria |
| L50.6 | Contact urticaria |
| L50.8 | Other urticaria |
| L50.9 | Urticaria, unspecified |
Injury, poisoning & external causes (3)
| ICD-10 | Covered diagnosis |
|---|---|
| T78.40XA | Allergy, unspecified, initial encounter |
| T78.40XD | Allergy, unspecified, subsequent encounter |
| T78.40XS | Allergy, unspecified, sequela |
Factors influencing health status (3)
| ICD-10 | Covered diagnosis |
|---|---|
| Z91.010 | Allergy to peanuts |
| Z91.013 | Allergy to seafood |
| Z91.040 | Latex allergy status |
How to use this list when billing
Put the patient's covered ICD-10 diagnosis on the claim line with J2357 and confirm your documentation supports medical necessity. Match the right product code (reference vs biosimilar) and units, and check the diagnosis against the article for your MAC, since the list above is National Government Services, Inc. policy.
LCD vs. Billing & Coding Article vs. NCD
An LCD (Local Coverage Determination) is a MAC's policy on whether a service is reasonable and necessary in its region, and its companion Billing & Coding Article holds the covered ICD-10 and HCPCS code lists. A NCD (National Coverage Determination), where one exists, applies nationwide. For Omalizumab (Xolair), the code lists live in Article A52448 (tied to LCD L33394) — CMS moved code lists out of LCDs and into Articles, which is why the diagnoses live in the Article, not the LCD.
Common Omalizumab (Xolair) denial reasons
| What you see | Why | Fix |
|---|---|---|
| CO-50 — not medically necessary | Diagnosis not in the covered list for J2357 | Bill a covered ICD-10 from the groups above, or document an exception |
| Diagnosis/units mismatch | Right dx but wrong product code or unit count | Match the J/Q code and units to the drug actually given (check JZ/JW wastage) |
| Covered by one MAC, denied by another | You used a different region's covered list | Use the Article for your MAC (coverage varies) |
| Non-covered / statutorily excluded dx | Diagnosis is on the non-covered list | Confirm against the Article's non-covered ICD-10 group |
Frequently asked questions
- Is Omalizumab (Xolair) covered by Medicare?
- Yes. Omalizumab (Xolair) (J2357) is covered under Medicare Part B as a physician-administered drug when billed for a medically necessary, covered diagnosis. Local coverage is defined by National Government Services, Inc. in Billing & Coding Article A52448, tied to LCD L33394.
- What diagnoses are covered for Omalizumab (Xolair) (J2357)?
- Medicare lists 17 covered ICD-10 diagnosis codes for J2357 under Article A52448. The full list is on this page, grouped by condition category. Coverage can vary by Medicare Administrative Contractor (MAC); confirm against the article that applies in your state.
- Which Medicare policy covers Omalizumab (Xolair)?
- Billing & Coding Article A52448 (v23), tied to LCD L33394 (“Drugs and Biologicals, Coverage of, for Label and Off-Label Uses”), published by National Government Services, Inc. and last updated 09/17/2025.
- Why was my Omalizumab (Xolair) claim denied as not medically necessary?
- The most common cause is an ICD-10 diagnosis on the claim that is not in the covered list for J2357. Confirm the patient's diagnosis is in the groups below, that documentation supports medical necessity, and that you are using the article for your MAC.
Related references
Covered is only half the answer.
You know the diagnosis is payable. Now quote the patient before the visit and catch underpayments: get Omalizumab (Xolair)'s exact Medicare allowed amount, your payer's rate vs. ASP+6%, and the patient's out-of-pocket — in about 30 seconds, free.
Estimate Omalizumab (Xolair) cost & patient owe →Source & verification
- Source
- CMS Medicare Coverage Database — Billing & Coding Article A52448 (v23), LCD L33394 “Drugs and Biologicals, Coverage of, for Label and Off-Label Uses” — National Government Services, Inc..
- CMS article last revised
- 09/17/2025 — the most recent revision CMS has published for this article.
- Page last reviewed by CareCost
- Jun 29, 2026 (coverage data retrieved 2026-06-28; we re-verify against CMS quarterly).
- Code licensing
- ICD-10-CM codes are public domain (CMS/CDC). CPT® codes are AMA-copyrighted and are intentionally not listed here — see the administration-code reference for those.
- Not advice
- This is general billing reference, not legal or billing advice. Always verify against the LCD/Article that applies to your MAC and patient.
- How we build this
- Compiled programmatically from the CMS Coverage API and reviewed by the CareCost Estimate editorial team against the source article. See our methodology and editorial policy.
- Spotted an error?
- Email editorial@carecostestimate.com.