Drug codes appear here only when a CMS NDC–HCPCS crosswalk lists at least one of this drug’s NDC packages. CodeRx never assigns a code from the name or ingredient.
J1120JJ-code: Drugs administered other than oral method; chemotherapy drugsActiveDerived calculation
Injection, acetazolamide sodium, up to 500 mg
Derived: 5 of 6 NDC package(s) for this drug appear in the CMS NDC–HCPCS crosswalk for J1120. CMS quarters Q1 2021 – Q4 2026
J-codes are permanent national codes for drugs and biologicals — most often clinician-administered (buy-and-bill) products paid under Medicare Part B — plus certain immunosuppressive, inhalation (via DME), and oral anticancer/antiemetic drugs. Units are reported in multiples of the dosage in the code descriptor.
03
NDC packages
Package NDCs from the FDA directory, normalized to the 11-digit 5-4-2 format used on claims.
Billable units per package for each NDC are listed in the NDC packages table above (CMS “BILLUNITSPKG”).
05
Reimbursement
Medicare Part B payment limits for the codes above, then how the home infusion per diem S-codes are paid. Commercial payer rates, AWP, and WAC are not included.
Medicare coverage is set nationally (NCDs) and by each Medicare Administrative Contractor (LCDs and Billing & Coding articles). These links open the official documents.
Diagnosis codes (ICD-10-CM) in Medicare billing articles
ICD-10-CM codes that Medicare contractors' Billing and Coding articles list as supporting medical necessity for this drug's HCPCS codes — covered diagnoses, not how often each is used. Washington (Noridian JF) articles come first; other contractors' articles are linked below.
No current Medicare Billing and Coding article lists J1120.
09
Code history
Quarterly changes to the HCPCS codes linked to this drug.
J1120
History for J1120
Quarterly file
Change
CMS action code
Details
Q1 2023
In earliest ingested file
N — No maintenance
Added date Jan 1, 1982
10
Data sources
11
Limitations and disclaimers
FDA NDC Directory data is submitted by labelers; FDA notes that inclusion does not mean the information was verified or that a product is approved, covered, or reimbursable.
HCPCS links are derived from CMS NDC–HCPCS crosswalks, which support ASP-based Part B payment and are not a complete list of billable NDCs.
Product class (brand, generic, biosimilar) is derived from the FDA marketing category and Purple Book license type, not from a commercial compendium.
Payment limits are Medicare Part B national limits; they do not reflect payer contracts, OPPS rates, 340B pricing, or acquisition cost.
Home infusion per diem S-codes are matched by therapy category from the FDA pharmacologic class and route, not from a CMS crosswalk. Payers choose which per diem codes they accept, and the right code can depend on the dosing schedule, infusion method, or daily volume.
Disclaimer. This application provides informational coding and reimbursement reference data. It does not constitute legal, clinical, coding, or billing advice. Codes, payment amounts, payer rules, and coverage policies can change. Verify all information with current CMS publications, the applicable payer, and your organization’s compliance policies before submitting a claim. CodeRx is not affiliated with or endorsed by CMS, FDA, Medicare, or any payer.
Official CMSCMSHCPCS Level II Quarterly Update (Alpha-Numeric HCPCS File)Q4 2026·Effective Oct 1, 2026 – Dec 31, 2026·Published Updated 09/23/2026·Imported Oct 15, 2026 05:52 UTCSource file (opens CMS website)
Derived calculationDrug-to-code links are aggregated from NDC-level CMS crosswalk rows.
Home infusion per diem (S-codes)
When a home infusion pharmacy dispenses this drug, the drug is billed with the code above and each day of pharmacy services, supplies, and equipment with a per diem S-code. CMS publishes no drug-to-per-diem crosswalk, so CodeRx picks the therapy category from the FDA pharmacologic class and route. S-codes are not payable by Medicare; confirm the code against the payer contract.
Not otherwise classified
Derived calculationVerification needed
No category matched · FDA class: Carbonic Anhydrase Inhibitor
S9379Infusion therapy with no specific per diem codeFits this drug’s routeCMS: Home infusion therapy, infusion therapy, not otherwise classified
S9542Injectable therapy with no specific per diem codeCMS: Home injectable therapy, not otherwise classified
No specific category was found in this drug’s FDA pharmacologic class. Use a specific code instead when the therapy is one CodeRx cannot detect: hydration (S9373–S9377), tocolytic (S9349), anti-spasmodic (S9363), blood products (S9538), or irrigation (S9590).
Not payable by Medicare — CMS coverage code I (all 2 codes)
Part B pricing indicator
00 — Not separately priced by Part B (all 2 codes)
National payment amount
None. No per diem code here is in the CMS Part B payment limit file for Q4 2026; CMS sets no national per diem rate.
Washington Apple Health (Medicaid)
Not on HCA’s Home Infusion Therapy/Parenteral Nutrition Program fee schedule (effective Jul 1, 2026), so these per diems are not separately paid. Home infusion is paid with the supply, pump, and nutrition codes in that schedule instead (below).
Billing unit
1 unit = 1 day on service (the CMS descriptor ends “per diem”)
Who sets the rate
Each commercial plan’s contract or state Medicaid fee schedule. Some payers reduce a second per diem billed for the same day.
Billed separately
The drug, with its own HCPCS code and units, and nursing visits — the CMS descriptor says “drugs and nursing visits coded separately”.
Washington Apple Health (Medicaid) home infusion fee schedule — 59 codes, effective Jul 1, 2026
Washington Apple Health (Medicaid): Home Infusion Therapy/Parenteral Nutrition Program fee schedule, effective Jul 1, 2026
Maximum allowable fees as published by HCA, per billing unit of each code. BR = by report (invoice required); DP = covered under another program (see comments); N/A = no separate rate for that area. HCA pays the lesser of the provider’s usual charge and the maximum allowable fee (WAC 182-553).
How Medicare pays for home infusion instead
Medicare pays no per diem. Under its home infusion therapy services benefit, a qualified home infusion supplier is paid per infusion day, and only for drugs given through a Medicare-covered external infusion pump:
Category 1 — IV anti-infective, pain management, chelation, pulmonary hypertension, inotropic, or other IV drug (not chemotherapy): G0068, first visit G0088
Category 2 — Subcutaneous immunotherapy or other subcutaneous infusion: G0069, first visit G0089
Category 3 — IV chemotherapy or other highly complex drug: G0070, first visit G0090
Verification neededCodeRx links to coverage documents instead of copying them: CMS distributes their code lists under AMA, ADA, and AHA license terms that limit reuse. Medicare Advantage, Medicaid, and commercial plans set their own coverage and prior-authorization rules.
Official CMSCMSHCPCS Level II Quarterly Update (Alpha-Numeric HCPCS File)Q4 2026·Effective Oct 1, 2026 – Dec 31, 2026·Published Updated 09/23/2026·Imported Oct 15, 2026 05:52 UTCSource file (opens CMS website)
Official state MedicaidWashington State HCAApple Health (Medicaid) Home Infusion Therapy/Parenteral Nutrition Program fee schedule2026-07-01·Effective Jul 1, 2026·Published July 1, 2026·Imported Oct 23, 2026 10:35 UTCSource file (opens Washington State HCA website)
Every import with its checksum is listed on the data sources page.