Quick answer
J1299Q5151Q5152
What Medicare pays for Eculizumab (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%) |
|---|---|---|---|
| J1299 | Inj, eculizumab, 2 mg | 2 mg | $44.699 |
| Q5151 | Inj, eculizumab-aagh, 2 mg | 2 mg | $31.928 |
| Q5152 | Inj, eculizumab-aeeb, 2 mg | 2 mg | $41.789 |
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 →
Eculizumab 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 J1300, Q5140, Q5141) 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 Eculizumab
The 18 codes below are the diagnoses National Government Services, Inc. accepts for J1300 under Article A54548, 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 — 18 covered diagnoses
Diseases of the genitourinary system (10)
| ICD-10 | Covered diagnosis |
|---|---|
| N00.6 | Acute nephritic syndrome with dense deposit disease |
| N00.B1 | Acute nephritic syndrome with idiopathic immune membranoproliferative glomerulonephritis (IC-MPGN) |
| N00.B2 | Acute nephritic syndrome with secondary immune complex membranoproliferative glomerulonephritis (IC-MPGN) |
| N01.6 | Rapidly progressive nephritic syndrome with dense deposit disease |
| N02.6 | Recurrent and persistent hematuria with dense deposit disease |
| N03.6 | Chronic nephritic syndrome with dense deposit disease |
| N04.6 | Nephrotic syndrome with dense deposit disease |
| N04.B1 | Nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN) |
| N04.B2 | Nephrotic syndrome with secondary immune complex membranoproliferative glomerulonephritis (IC-MPGN) |
| N07.6 | Hereditary nephropathy, not elsewhere classified with dense deposit disease |
Blood, blood-forming organs & immune disorders (4)
| ICD-10 | Covered diagnosis |
|---|---|
| D59.31 | Infection-associated hemolytic-uremic syndrome |
| D59.32 | Hereditary hemolytic-uremic syndrome |
| D59.39 | Other hemolytic-uremic syndrome |
| D59.5 | Paroxysmal nocturnal hemoglobinuria [Marchiafava-Micheli] |
Diseases of the nervous system (3)
| ICD-10 | Covered diagnosis |
|---|---|
| G36.0 | Neuromyelitis optica [Devic] |
| G70.00 | Myasthenia gravis without (acute) exacerbation |
| G70.01 | Myasthenia gravis with (acute) exacerbation |
Injury, poisoning & external causes (1)
| ICD-10 | Covered diagnosis |
|---|---|
| T86.19 | Other complication of kidney transplant |
How to use this list when billing
Put the patient's covered ICD-10 diagnosis on the claim line with J1300 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 Eculizumab, the code lists live in Article A54548 — CMS moved code lists out of LCDs and into Articles, which is why the diagnoses live in the Article, not the LCD.
Common Eculizumab denial reasons
| What you see | Why | Fix |
|---|---|---|
| CO-50 — not medically necessary | Diagnosis not in the covered list for J1300 | 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 Eculizumab covered by Medicare?
- Yes. Eculizumab (J1300) 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 A54548.
- What diagnoses are covered for Eculizumab (J1300)?
- Medicare lists 18 covered ICD-10 diagnosis codes for J1300 under Article A54548. 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 Eculizumab?
- Billing & Coding Article A54548 (v35), published by National Government Services, Inc. and last updated 09/17/2025.
- Why was my Eculizumab 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 J1300. 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 Eculizumab'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 Eculizumab cost & patient owe →Source & verification
- Source
- CMS Medicare Coverage Database — Billing & Coding Article A54548 (v35) — 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.