No. J1120 is a HCPCS Level II code, maintained by CMS, that identifies the drug supplied. CPT codes are five-digit numbers from the AMA that describe services. Giving the drug, for example an injection or infusion, is usually reported with a separate CPT administration code.

What NDCs are billed under J1120?

CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 7 NDCs under J1120, for Acetazolamide and Acetazolamide Sodium. The table on this page shows each one with its billing units per package.

What is the Medicare payment limit for J1120?

$23.951 per 500 mg, effective October 1, 2026 through December 31, 2026, from CMS's Part B drug payment limit file. Multiply by the units billed for the allowed amount before deductible and coinsurance. It is not a coverage decision.

J1120 J-Code: Acetazolamide sodium — Billing Units & NDCs

In short

J1120 is the HCPCS Level II code for injection, acetazolamide sodium, up to 500 mg. CMS assigns NDCs for Acetazolamide and Acetazolamide Sodium to it. The Medicare Part B payment limit is $23.951 per unit (October 1, 2026 through December 31, 2026).

Code

CMS HCPCS file

HCPCS codeJ1120

Billing unitSee descriptor

Descriptor: Injection, acetazolamide sodium, up to 500 mg
Short descriptor: Acetazolamid sodium injectio
Code set: HCPCS Level II, maintained by CMS
Effective: Jan 1, 1997

Medicare Part B payment limit

CMS ASP file

Payment limit per unit$23.951

Per500 mg

Coinsurance20%

Effective October 1, 2026 through December 31, 2026. Payment allowance limits subject to the ASP methodology are based on 2Q26 ASP data. A payment limit is not a coverage decision; the Medicare contractor decides coverage. CMS ASP pricing files

Units and claim line

Enter the dose to get the units and the NDC line for the CMS-1500 and the 837P.

HCPCS units

Modifier

NDC (11-digit)

NDC unit qualifier

NDC quantity

Enter the units to build the claim line.

NDCs billed under J1120

CMS’s ASP NDC–HCPCS crosswalk (effective October 1, 2026 through December 31, 2026) assigns 7 NDCs to J1120 for Acetazolamide and Acetazolamide Sodium. Billing units per package are CMS’s figures for this code’s unit.

NDCs assigned to J1120 in the CMS ASP crosswalk
Drug	NDC (11-digit)	Labeler	Package	Billing units per package
Acetazolamide	25021-0839-20	Sagent Pharmaceuticals	1	1
Acetazolamide Sodium	00143-9006-01	Hikma Pharmaceuticals USA Inc.	1	1
Acetazolamide Sodium	00143-9503-01	Hikma Pharmaceuticals USA Inc.	1	1
Acetazolamide Sodium	23155-0313-31	Heritage Pharmaceuticals Inc.	1	1
Acetazolamide Sodium	23155-0831-31	Heritage Pharmaceuticals Inc.	1	1
Acetazolamide Sodium	39822-0190-01	XGen Pharmaceuticals DJB, Inc.	1	1
Acetazolamide Sodium	67457-0853-50	Mylan Institutional LLC	1	1

J1120: common questions

Is J1120 a CPT code?: No. J1120 is a HCPCS Level II code, maintained by CMS, that identifies the drug supplied. CPT codes are five-digit numbers from the AMA that describe services. Giving the drug, for example an injection or infusion, is usually reported with a separate CPT administration code. CPT codes for drug administration.
What NDCs are billed under J1120?: CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 7 NDCs under J1120, for Acetazolamide and Acetazolamide Sodium. The table on this page shows each one with its billing units per package.
What is the Medicare payment limit for J1120?: $23.951 per 500 mg, effective October 1, 2026 through December 31, 2026, from CMS's Part B drug payment limit file. Multiply by the units billed for the allowed amount before deductible and coinsurance. It is not a coverage decision.

J1120 — Injection, acetazolamide sodium, up to 500 mg