J1120
J1120 – Injection, acetazolamide sodium, up to 500 mg · NDC Crosswalk & Billing Units
HCPCS Level II J-code · Medicare Part B drug billing
J-code
● 7 NDCs crosswalked per 500 MG $28.127/unit ASP+6%
📋 J1120 summary
J1120 is a HCPCS Level II J-code used to bill acetazolamide sodium, up to 500 mg, billed per 500 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 J1120: Acetazolamide
Code J1120
Billing unit 500 MG Payment limit $28.127/unit NDC-Crosswalk 7
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 codeJ1120
DescriptorInjection, acetazolamide sodium, up to 500 mg
Billing unit500 MG
Payment limit / unit$28.127
Est. ASP / unit$26.535 est.
Mapped NDCs7
Data periodQ3 2026
Last updated2026-08-20
💊 About Acetazolamide DRUG GUIDE
Acetazolamide is used as an add-on treatment for several conditions.
Across tablets and the intravenous injection, it treats glaucoma (including open-angle and secondary glaucoma, and before surgery for acute angle-closure glaucoma), certain types of epilepsy (centrencephalic seizures, including petit mal), edema (fluid buildup) due to congestive heart failure, and drug-induced edema.Acetazolamide extended-release capsules are specifically indicated for the prevention or reduction of acute mountain sickness symptoms — such as headache, nausea, and dizziness — in climbers attempting rapid ascent.
Acetazolamide tablets and the intravenous injection are also indicated for acute mountain sickness.
Clinical overview from our editorial drug guide for Acetazolamide. 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
$28.127
Est. ASP / unit
$26.535 est.
Est. after 2% sequester
$27.564
HCPCS dosage
500 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, acetazolamide sodium, up to 500 mg
CoverageD — Special coverage instructions apply
Pricing indicator51 — Drug — priced under the ASP methodology
Type of service1 — Medical care
BETOS-2O1E
ASC payment group—
Action codeN — No maintenance this year
Effective date1997-01-01
Date added1982-01-01
Source: CMS HCPCS Level II code file (imported via admin).
🧮 Dosing & billing-units calculator HCPCS UNITS
One billing unit of J1120 = 500 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 J1120 WITH EST. MEDICARE PAY
7 NDCs map to J1120. Bill units = how many HCPCS units one package represents. Est. pay / pkg = payment limit ($28.127/unit) × that package's bill units.
| NDC (11-digit) | Drug | Labeler | Package | Strength | Bill units | Est. pay / pkg | NADAC / unit | Status | Source |
|---|---|---|---|---|---|---|---|---|---|
| 00143-9006-01 | AcetaZOLAMIDE 500 mg/1 INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | Hikma | 1 VIAL in 1 CARTON (0143-9006-01) / 1 INJ... | 500 mg/1 | 1 | $28.13 | — | ● Active | CMS ASP |
| 00143-9503-01 | AcetaZOLAMIDE 500 mg/1 INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | Hikma | 1 VIAL in 1 BOX, UNIT-DOSE (0143-9503-01)... | 500 mg/1 | 1 | $28.13 | — | ● Active | CMS ASP |
| 23155-0313-31 | Acetazolamide 500 mg/5mL INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | Heritage | 5 mL in 1 VIAL, GLASS (23155-313-31) | 500 mg/5mL | 1 | $28.13 | — | ● Active | CMS + PDAC |
| 23155-0831-31 | Acetazolamide 500 mg/5mL INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | Heritage | 1 VIAL, GLASS in 1 CARTON (23155-831-31)... | 500 mg/5mL | 1 | $28.13 | — | ● Active | CMS ASP |
| 25021-0839-20 | Acetazolamide 500 mg/5mL INJECTION, POWDER, FOR SOLUTION | Sagent | 1 VIAL in 1 CARTON (25021-839-20) / 5 mL... | 500 mg/5mL | 1 | $28.13 | — | ● Active | CMS ASP |
| 39822-0190-01 | Acetazolamide 500 mg/5mL INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | XGen | 1 VIAL, GLASS in 1 CARTON (39822-0190-1)... | 500 mg/5mL | 1 | $28.13 | — | ● Active | CMS ASP |
| 67457-0853-50 | Acetazolamide 500 mg/5mL INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | Mylan | 1 VIAL in 1 CARTON (67457-853-50) / 5 mL... | 500 mg/5mL | 1 | $28.13 | — | ● Active | CMS + PDAC |
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 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
$0.00
Medicare paid
$127.58
Submitted services
14
Denial rate
100.0%
Submitted charges
$555.66
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 J1120 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.
📊 What bills under J1120
J-codes are billing codes often used for drugs billed under the medical benefit. This connects the billing code to the NDC package records it covers, by ingredient and labeler.
NDC products by ingredient
NDC products by labeler
🗃️ 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 + DMEPDAC (PDAC)
7 NDCs 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
No reportable utilization
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.
❓ J1120 billing FAQ
What is HCPCS code J1120?
J1120 is a HCPCS Level II J-code used to bill Injection, acetazolamide sodium, up to 500 mg under Medicare Part B and most medical (not pharmacy) benefits.
What is the billing unit for J1120?
One unit of J1120 represents 500 MG. Report the number of units equal to the dose administered divided by 500 MG.
How many units of J1120 should I bill?
Divide the dose administered by the code's unit size (500 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 J1120?
The Medicare Part B payment limit is $28.127 per unit (Q3 2026), based on ASP + 6%. After the 2% sequester the effective payment is about $27.564 per unit. Payment limits are revised quarterly.
Which NDCs bill under J1120?
7 NDCs currently map to J1120 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 J1120 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.