J9331
J9331 – Injection, sirolimus protein-bound particles, 1 mg · NDC Crosswalk & Billing Units
HCPCS Level II J-code · Medicare Part B drug billing
J-code
● 1 NDC crosswalked per 1 MG $91.030/unit ASP+6%
📋 J9331 summary
J9331 is a HCPCS Level II J-code used to bill sirolimus protein-bound particles, 1 mg, billed per 1 MG. The number of billing units to report depends on the dose administered and the NDC/package billed — use the calculator below.
Brand names associated with J9331: Fyarro
Code J9331
Billing unit 1 MG Payment limit $91.030/unit NDC-Crosswalk 1
Quarter Q3 2026
RxCUI Atlas Trace the drug concept →
⚠ An NDC↔HCPCS crosswalk and a published payment limit do not guarantee payer coverage or payment. Always verify the current payer policy and claim format before billing.
🗂️ Key billing facts
HCPCS codeJ9331
DescriptorInjection, sirolimus protein-bound particles, 1 mg
Billing unit1 MG
Payment limit / unit$91.030
Est. ASP / unit$85.877 est.
Mapped NDCs1
Data periodQ3 2026
Last updated2026-08-20
💊 About Sirolimus (with albumin) Injection DRUG GUIDE
Fyarro (sirolimus with albumin) injection is approved to treat adult patients with locally advanced unresectable or metastatic malignant perivascular epithelioid cell tumor (PEComa) — a rare type of soft-tissue tumor.
This includes tumors that cannot be surgically removed or that have spread to other parts of the body.
Clinical overview from our editorial drug guide for Sirolimus (with albumin) Injection. For billing reference, see the sections above.
🧾 Billing & reimbursement HCPCS · CMS · EFF. Q3 2026
📅 Payment limits effective Q3 2026 — from the CMS Medicare Part B Payment Limit File (revised quarterly).
Medicare payment limit / unit
$91.030
Est. ASP / unit
$85.877 est.
Est. after 2% sequester
$89.209
HCPCS dosage
1 MG
The CMS payment limit is the Medicare Part B drug allowance (ASP + 6%, statutory). After the 2% federal sequester the effective payment is ≈ ASP + 4.3%; estimated ASP = payment limit ÷ 1.06. Source: CMS Medicare Part B Payment Limit File (quarterly), Q3 2026.
Full HCPCS code details (official CMS record)
Long descriptionInjection, sirolimus protein-bound particles, 1 mg
CoverageC — Carrier/MAC judgment
Pricing indicator51 — Drug — priced under the ASP methodology
Type of service1 — Medical care
BETOS-2O1E
ASC payment groupYY
Action codeN — No maintenance this year
Effective date2022-07-01
Date added2022-07-01
Source: CMS HCPCS Level II code file (imported via admin).
🧮 Dosing & billing-units calculator HCPCS UNITS
One billing unit of J9331 = 1 mg. Enter a regimen to convert dose → billing units and project a full course.
Billing units = dose ÷ HCPCS unit size. Most payers require whole units — round per the payer's policy. “Est. Medicare pay” uses the current payment limit. For single-dose vials, drug discarded after administration may be separately billable with modifier JW (JZ when none is discarded) where allowed. Always verify payer-specific rounding before billing.
🔁 NDCs that bill under J9331 WITH EST. MEDICARE PAY
1 NDC map to J9331. Bill units = how many HCPCS units one package represents. Est. pay / pkg = payment limit ($91.030/unit) × that package's bill units.
| NDC (11-digit) | Drug | Labeler | Package | Strength | Bill units | Est. pay / pkg | NADAC / unit | Status | Source |
|---|---|---|---|---|---|---|---|---|---|
| 80803-0153-50 | FYARRO Sirolimus 5 mg/mL INJECTION, POWDER, LYOPHILIZED, FOR SUSPENSION | Aadi | 1 VIAL, SINGLE-USE in 1 CARTON (80803-153-... | 5 mg/mL | 100 | $9,103.00 | — | ● Active | CMS ASP |
NDC→HCPCS mappings come from the CMS ASP NDC-HCPCS crosswalk; additional DME MAC / DMEPOS mappings come from PDAC and are labeled separately. NADAC from CMS (weekly). “Status” reflects the product's marketing / obsolete flag in the NDC directory. Presence or absence here does not determine Medicare coverage. Linked NDCs open the full product page.
📊 Medicare utilization & spend CMS · PART B · 2026 (Q1)
Period
Total Part B spend
$2.4M
Claims
150
Beneficiaries
28
Spend / beneficiary
$85,732.17
Spend / claim
$16,003.34
Trend by period
Where J9331 ranks among Part B drugs · 2026 (Q1) · neighbors ±5
Total spending — #308 of 824
#303
BELRAPZO* J9036
$2.6M
#304
JIVI J7208
$2.56M
#305
SUSVIMO J2779
$2.53M
#306
GELSYN-3 J7328
$2.43M
#307
BORUZU J9054
$2.41M
#308
FYARRO J9331
$2.4M
#309
PANHEMATIN J1640
$2.4M
#310
EPYSQLI Q5151
$2.38M
#311
BELEODAQ J9032
$2.35M
#312
LOQTORZI J3263
$2.35M
#313
ALBUKED-5* P9045
$2.29M
Total claims — #586 of 824
#581
CARVYKTI Q2056
156
#582
GANCICLOVIR SODIUM J1570
154
#583
ADRENALIN(J0165)* J0165
152
#584
AVYCAZ J0714
151
#585
NUWIQ J7209
150
#586
FYARRO J9331
150
#587
ZIIHERA J9276
145
#588
CLEVIPREX J0759
144
#589
SURGRAFT TL, PER SQ... Q4263
144
#590
UZEDY J2799
143
#591
KOVALTRY J7211
142
Top Medicare Part B drugs by the selected metric. Click any drug to open its J-code page. Source: CMS Medicare Quarterly Part B Spending by Drug.
Full breakdown by period (2)
| Period | Total spend | Beneficiaries | Claims | $/beneficiary | $/claim |
|---|---|---|---|---|---|
| 2026 (Q1) | $2.4M | 28 | 150 | $85,732.17 | $16,003.34 |
| 2025 (Q1-Q4) | $10.44M | 45 | 583 | $232,058.57 | $17,911.90 |
Provider-administered (Part B) spend, calculated for the whole HCPCS code (CMS does not publish Medicare spend per individual NDC). Self-administered use is covered under Part D instead. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part B Spending by Drug (data.cms.gov), updated quarterly.
📈 Medicare Part B claims detail CMS PSPS · 2024
Calendar-year 2024 Medicare Part B fee-for-service activity for this HCPCS code, summed across all carriers, localities and specialties (CMS Physician/Supplier Procedure Summary). A “service” is one billed line/unit — not one claim — so counts run higher than claim counts.
Allowed charges
$3.85M
Medicare paid
$2.86M
Submitted services
39,667
Denial rate
1.5%
Allowed / service
$98.43
Submitted charges
$10.71M
Source: CMS Physician/Supplier Procedure Summary (PSPS), CY2024 — Medicare Part B carrier + DME fee-for-service claims (excludes Medicare Advantage). Figures are for the whole HCPCS code, which may cover uses beyond this drug. ⚠ CMS hides any figure covering fewer than 11 patients (a privacy rule), so totals — especially denials and low-volume codes — run a little low.
🗺️ Where J9331 is utilized
⏳
The geographic utilization map is building for this code — it aggregates millions of CMS Part B claim lines, then caches the result. Refresh in a moment; if it doesn’t appear, this code may have no reportable Part B utilization.
🗃️ Data sources & freshness
Every figure on this page is computed from public datasets. Here's what each section draws on and how current it is.
HCPCS code & descriptor
CMS HCPCS Level II code file
Loaded
Payment limit & billing unit
CMS Medicare Part B ASP Pricing File (quarterly)
Q3 2026 · as of 2026-08-20
NDC ↔ HCPCS crosswalk
CMS ASP NDC-HCPCS crosswalk
1 NDC mapped
NADAC acquisition cost
CMS National Average Drug Acquisition Cost (weekly)
Not available for mapped NDCs
Utilization & spend
CMS Part B Spending by Drug · PSPS · Physician & Other Practitioners
Latest data year 2026
Figures are estimates for reference and may lag the source files. Always verify against the current CMS files and your payer's policy before submitting claims.
⚠️ Practical billing caveats
- A crosswalk is not coverage. An NDC mapping or a published payment limit does not guarantee a payer will cover or pay this code. Check the specific plan's policy.
- Units ≠ milligrams. Bill the number of HCPCS units (dose ÷ the code's unit size), not the milligram dose. Use the calculator above.
- Discarded drug. For single-dose vials, drug discarded after administration may be separately billable with modifier JW (and JZ when nothing is discarded) where the payer allows.
- Rounding & partial units. Many payers require whole units; round per the payer's policy, not automatically up.
- The code can cover more than this drug. Some HCPCS codes span multiple products or strengths — confirm the exact code for the product administered.
- Figures lag. ASP limits change quarterly and utilization data are released with a delay. Verify against the current CMS files before billing.
❓ J9331 billing FAQ
What is HCPCS code J9331?
J9331 is a HCPCS Level II J-code used to bill Injection, sirolimus protein-bound particles, 1 mg under Medicare Part B and most medical (not pharmacy) benefits.
What is the billing unit for J9331?
One unit of J9331 represents 1 MG. Report the number of units equal to the dose administered divided by 1 MG.
How many units of J9331 should I bill?
Divide the dose administered by the code's unit size (1 MG) to get the number of billing units, then round per your payer's policy. The calculator on this page converts a dose into billing units and projects a full course.
How much does Medicare pay for J9331?
The Medicare Part B payment limit is $91.030 per unit (Q3 2026), based on ASP + 6%. After the 2% sequester the effective payment is about $89.209 per unit. Payment limits are revised quarterly.
Which NDCs bill under J9331?
1 NDC currently map to J9331 in the CMS ASP NDC-HCPCS crosswalk. See the NDC crosswalk table above for each product, package, billing units and estimated reimbursement.
Does a crosswalk mean J9331 is covered?
No. An NDC-to-HCPCS crosswalk and a published payment limit do not guarantee coverage or payment. Coverage depends on the payer, the diagnosis and the site of care — always verify the current policy before billing.
For professional billing reference only — verify against the current CMS files before submitting claims.