Darzalex Faspro (daratumumab and hyaluronidase-fihj) cost per dose and what the patient owes

$57.051 per 10 mg is Part B's ASP+6% rate for Q3 2026. Once the $283 Part B deductible is met, the patient owes the remaining 20% coinsurance on the drug and its administration, with no annual out-of-pocket maximum to cap it — $2,068.20 on a single 1,800 mg dose. That figure does not move with the regimen: every schedule in the label uses the same 1,800 mg dose, so the claim size is identical whether the visit falls in week 1 or year three; only the calendar between visits changes. Full explanation: How Medicare Part B drug cost sharing works →

Medicare pays J9144 per 10 mg billing unit, not per vial or per dose. Darzalex Faspro's labeled dose is a flat 1,800 mg for every indication, drawn whole from one 1,800 mg single-dose vial — so the allowed drug amount is the same $10,269.18 every time, and JZ belongs on every claim because there is no drug left over to discard.

Faspro's dose is flat: 1,800 mg every visit, no matter the patient's weight. IV Darzalex (J9145) is dosed by weight, 16 mg/kg. At the site's reference weight of 80 kg, that is 1,280 mg — less drug than Faspro's flat dose — but the infusion adds its own administration codes, and the two visits land close together.

At 80 kg, Faspro's visit allows $679.99 more than a later IV infusion ($10,340.99 against $9,661.00) and $594.82 more than the longer first IV infusion ($9,746.17) — the price of trading 3 to 7 hours in the chair for a 5-minute injection. Because the IV dose scales with weight and Faspro's does not, that gap narrows as the patient gets heavier and reverses above roughly 86 kg, where the IV drug cost alone exceeds what Faspro's flat dose plus its short injection code allow. CareCost does not compare drugs on clinical grounds; this is the allowed-amount trade only.

The label doses Faspro on a cycle, not a fixed course: weekly for 8 doses, every 2 weeks for 8 doses, then every 4 weeks until progression. That is 23 doses in the first year (8 + 8 + 7) on the 4-week regimens and on monotherapy, settling to 13 doses a year after that. Every one of those 23 doses bills the identical $10,340.99 allowed amount — the schedule changes the calendar, never the claim.

Twenty-three doses at $10,340.99 allowed comes to $237,842.77 for the year. The patient's 20% coinsurance on that, before any Medigap plan or assistance program, is $47,568.55. Other regimens run different calendars — VMP's 6-week cycle carries 22 doses in year one, the transplant regimens pause for the transplant itself — but every regimen bills the same 180-unit, $10,340.99 claim per visit; only the visit count for the year differs.

For the reference dose — 1,800 mg, 180 units, drug + the 96401 administration code — Medicare allows $10,340.99, and the Part B coinsurance on that is $2,068.20. Plans A, B, C, D, F, G, M and N cover that coinsurance in full, so those patients owe nothing per dose once the $283 deductible is met. Plans K and L do not — and because every dose repeats this claim, the plan's annual out-of-pocket maximum arrives fast.

A Plan K patient owes $1,288.80 at the dose that lands before the deductible is met, and $1,034.10 at the dose after it. On the 23-dose first-year schedule, that crosses Plan K's $8,000 annual out-of-pocket maximum on the eighth dose of the year — the last of the weekly doses, week 8 on the 4-week schedule — after which the plan covers the coinsurance in full for the rest of the year. See what each Medigap plan (A–N) owes on this claim →

Only the letters that leave this patient a balance are listed here. Every other letter, the high-deductible F/G variants, Plan N's per-visit copay carve-out, and the MACRA rule closing Plans C and F to new enrollees are covered at Medigap Plans A–N. The schedule slows to every 4 weeks after week 24, so a Plan K patient's out-of-pocket maximum, once crossed, stays crossed for the remaining doses of the year — the cap resets every January 1.

Commercial payers negotiate their own rate for J9144, not ASP+6% — our corpus holds published rates from all 37 of 37 payers checked, including Aetna, UnitedHealthcare, Cigna, Anthem, Regence, Premera and Kaiser. Aetna's all-states median is $57.08 per 10 mg unit against Medicare's $57.051, putting a 1,800 mg dose at $10,274.40 before benefits.

Rates move by state as well as by payer, which is why the estimator above takes one. What the patient owes then depends on their specific benefits. Full explanation: How commercial drug reimbursement works →

Darzalex Faspro is a short in-office subcutaneous injection into the abdomen, not an infusion, so claims bill under the physician fee schedule's chemotherapy-administration code (96401) rather than a hospital-outpatient facility fee. CareCost's payer-policy library does not yet cover oncology, so this page makes no payer-count or rule-count claim for daratumumab — use the payer's own medical policy for prior-authorization requirements. A myeloma or AL amyloidosis prior authorization typically asks for the diagnosis code, the regimen and line of therapy, and confirmation that pre-medication was given. CMS Medicare Coverage Database →

The Q2 2026 rate ($55.032 per 10 mg) applied to a 1,800 mg dose is $9,905.76 in drug alone; the current Q3 2026 rate applied to the same 1,800 mg dose is $10,269.18. Use the quarter that is actually in effect for the claim's date of service.

Janssen's CarePath / J&J withMe Savings Program is commercial only — it excludes Medicare, Medicaid, TRICARE, VA and other government plans. An eligible patient pays as little as $5 per dose toward the drug; Janssen states a maximum program benefit applies per calendar year but does not publish the amount. The program covers the drug only, not the $71.81 96401 line or the pre-medication.

The Johnson & Johnson Patient Assistance Foundation provides free drug to qualifying uninsured patients, shipped to the provider for up to a year and renewable. See both programs, with current status →

Sources: CMS ASP pricing files (Q3 2026); Medicare physician fee schedule (96401, national non-facility); DailyMed label (setid 4bb241af-4299-4373-8762-2d6709515db0, Revised 1/2026); NLM Clinical Table Search Service (ICD-10-CM); Medicare Part B deductible (2026); Medicare Rights Center 2026 Medigap plan benefits chart; 37 commercial payer published price files (Q2 2026); CMS Medicare Coverage Database; jnjwithme.com and jjpaf.org for the Darzalex Faspro programs (data/programs/J9144.json, generated from the live programs corpus).

Reviewed September 19, 2026 by Erin Rose, CareCost Estimate founder. Methodology →