Ultomiris (J1303) cost and reimbursement per infusion

$226.454 per 10 mg ($22.6454/mg) is Part B's ASP+6% rate for Q4 2026. At the 3,300 mg maintenance band (60 to under 100 kg, the worked example on this page) the drug alone runs $74,729.82, and the patient's 20% coinsurance on the full claim is $14,959.39 once the $283 Part B deductible is met, with no annual out-of-pocket maximum to cap it. Full explanation: How Medicare Part B drug cost sharing works →

Medicare pays J1303 per 10 mg billing unit, not per vial or per dose. A 3,300 mg dose is 330 billing units — divide the ordered mg by 10, not by either vial size (300 mg or 1,100 mg).

What the loading dose and the maintenance year cost

Each maintenance band draws to zero waste under the least-waste rule: ten 300 mg vials for 3,000 mg, three 1,100 mg vials for 3,300 mg, and three 1,100 mg vials plus one 300 mg vial for 3,600 mg, all billed JZ. The loading dose that opens treatment is weight-banded too, given once and separate from the maintenance schedule — at 60 to under 100 kg it's 2,700 mg (270 units, $61,142.58 as a drug line), with the first maintenance dose following 2 weeks later. A pharmacy short on 300 mg vials that draws two 1,100 mg plus two 300 mg vials instead reports the unused 100 mg (10 units, $2,264.54) on a JW line.

The 7-infusion maintenance year at 3,300 mg, $74,796.96 allowed per infusion, runs $523,578.72 before the sequester. The first year adds one more claim on top of that for the 2,700 mg loading dose, billed once before the every-8-week maintenance schedule starts.

For the reference patient — 3,300 mg, 330 units, drug plus the 96365 administration code — Medicare allows $74,796.96, and the Part B coinsurance on that is $14,959.39. Plans A, B, C, D, F, G, M and N cover that coinsurance in full, so those patients owe nothing per infusion once the $283 deductible is met. Plans K and L do not, and because Ultomiris is billed every 8 weeks, most claims in a plan year land after the deductible is already met. The infusion that lands before the deductible is met costs a Plan K patient $7,734.39; every infusion after it costs $7,479.69. Plan K's and Plan L's coinsurance shares are large enough that a single infusion can be most or all of what the plan lets the patient owe in a year, so the plan's own annual out-of-pocket limit, rather than the deductible alone, is worth checking before the second infusion. See what each Medigap plan (A–N) owes on this claim →

Only the letters that leave this patient a balance are listed. The full A–N grid, the high-deductible variants, Plan N’s office-visit carve-out and the MACRA restriction on Plans C and F are at Medigap Plans A–N.

Commercial payers negotiate their own rate for J1303, not ASP+6%. Our corpus holds published rates from 36 of 36 payer files, and Aetna's all-states median is $232.46 per unit (10 mg), putting the 330-unit maintenance dose at $76,711.80 before benefits. That rate itself differs by payer and by state, and what the patient ultimately owes comes down to their specific plan benefits. Full explanation: How commercial drug reimbursement works →

The per-unit rate alone does not say which claim costs more; the dose sets that. Soliris, Alexion’s earlier complement inhibitor, carries no ASP row in the pricing file after Q1 2025, so it prices here as unpriced this quarter, along with its biosimilars Bkemv and Epysqli. Piasky, Genentech’s PNH-only complement inhibitor, is the one priced alternative in the family at $551.51 per 10 mg, more than double Ultomiris’s rate. The family file lists no ravulizumab-cwvz biosimilar.

On a commercial plan, the Alexion OneSource Co-pay Program brings the Ultomiris drug cost to as little as $0 per prescription, up to $15,000 a year, and covers the drug line only — not the 96365 administration or an office visit, which are billed separately. It excludes Medicare, Medicaid, TRICARE, VA and other government program patients. The arithmetic on that cap is blunt: at 20% coinsurance priced at the Medicare reference rate, the drug line alone on one 3,300 mg infusion is $14,945.96, so a single claim can use up nearly the entire $15,000 annual card. The second infusion in a plan year is where a foundation fund and the patient's own plan out-of-pocket maximum start to matter more than the manufacturer card. Uninsured or underinsured patients may qualify for free drug instead, through the separate Alexion OneSource Patient Assistance Program.

Seven foundation funds are open across Ultomiris's four indications: PAN's paroxysmal nocturnal hemoglobinuria fund ($9,500/year) and The Assistance Fund's PNH fund (open, no stated maximum); The Assistance Fund's atypical hemolytic uremic syndrome fund (open, no stated cap); PAN's myasthenia gravis fund ($10,000/year, plus a separate premium-assistance fund) and The Assistance Fund's myasthenia gravis fund (open; amount not published, see program); and The Assistance Fund's and Good Days' neuromyelitis optica spectrum disorder funds, both open, Good Days by direct contact for the amount. See every program for this patient, with current status →

Sources: CMS ASP pricing files (Q4 2026); Medicare physician fee schedule (96365, 99214, national non-facility); Medicare Part B deductible (2026); Medicare Rights Center 2026 Medigap plan benefits chart; 36 commercial payer published price files (Q2 2026); Alexion OneSource Co-pay Program and Patient Assistance Program terms (alexiononesource.com, verified April 8, 2026).

Reviewed September 21, 2026 by Erin Rose, CareCost Estimate founder. Methodology →