J1561 is the HCPCS code for: Injection, immune globulin, (gamunex-c/gammaked), non-lyophilized (e.g., liquid), 500 mg. In 2024, 206 providers billed J1561 1,819,367 times, with an estimated $69.7M paid by Medicare.
J1561 is a Part B drug code: Medicare pays an ASP-based rate of $49.01 per 500 mg (2026 Q3 ASP drug pricing file). Total payment per patient depends on the dose billed.
A billed "service" on this code is one 500 mg unit, not one patient visit — that's why the service counts below run high.
What Medicare actually paid per service in 2024, on average: $38.33 (observed payment across all settings and modifiers — not a fee-schedule rate).
The top 5 billers nationally, ranked by 2024 Medicare service volume.
| # | Provider | Specialty | Location | Services | Est. Medicare paid |
|---|---|---|---|---|---|
| 1 | Guy Burrows, M.D. | Neurology | Shenandoah, TX | 345,020 | $13.3M |
| 2 | Philip Blum, MD | Neurology | Houston, TX | 48,678 | $1.9M |
| 3 | Bela Ajtai, MD, PHD | Neurology | Amherst, NY | 44,180 | $1.7M |
| 4 | Jeffrey Weber, M.D. | Gastroenterology | Milwaukee, WI | 38,330 | $1.5M |
| 5 | John Storheim, D.O. | Anesthesiology | Grand Junction, CO | 29,828 | $1.1M |
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