No. J9100 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 J9100?

CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 9 NDCs under J9100, for Cytarabine. The table on this page shows each one with its billing units per package.

What is the Medicare payment limit for J9100?

$0.853 per 100 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.

What is one billing unit of J9100?

One unit of J9100 is 100 mg, as stated in the code's descriptor. Units to report = dose given ÷ 100 mg.

J9100 J-Code: Cytarabine — Billing Units & NDCs

In short

J9100 is the HCPCS Level II code for injection, cytarabine, 100 mg. CMS assigns NDCs for Cytarabine to it. One billing unit is 100 mg. The Medicare Part B payment limit is $0.853 per unit (October 1, 2026 through December 31, 2026).

Code

CMS HCPCS file

HCPCS codeJ9100

Billing unit100 mg

Descriptor: Injection, cytarabine, 100 mg
Short descriptor: Cytarabine hcl 100 mg inj
Code set: HCPCS Level II, maintained by CMS
Effective: Jan 1, 2009

The billing unit is read from the descriptor. Confirm it against the CMS file before billing.

Medicare Part B payment limit

CMS ASP file

Payment limit per unit$0.853

Per100 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

Units = dose given ÷ 100 mg. For example, 10000 mg is 100 units. Enter the dose to get the units and the NDC line for the CMS-1500 and the 837P.

Dose given (mg)

HCPCS units (1 unit = 100 mg)

Modifier

NDC (11-digit)

NDC unit qualifier

NDC quantity

Enter the dose given to build the claim line.

NDCs billed under J9100

CMS’s ASP NDC–HCPCS crosswalk (effective October 1, 2026 through December 31, 2026) assigns 9 NDCs to J9100 for Cytarabine. Billing units per package are CMS’s figures for this code’s unit.

NDCs assigned to J9100 in the CMS ASP crosswalk
Drug	NDC (11-digit)	Labeler	Package	Billing units per package
Cytarabine	25021-0223-20	Sagent Pharmaceuticals	20	20
Cytarabine	25021-0229-05	Sagent Pharmaceuticals	5 × 5	5
Cytarabine	61703-0155-01	Pfizer Inc	20	20
Cytarabine	61703-0303-46	Pfizer Inc	50	10
Cytarabine	61703-0304-36	Pfizer Inc	25	5
Cytarabine	61703-0305-38	Pfizer Inc	5 × 5	5
Cytarabine	61703-0319-22	Pfizer Inc	20	20
Cytarabine	63323-0120-20	FreseniUS Kabi USA, LLC	1	20
Cytarabine	71288-0109-20	Meitheal Pharmaceuticals Inc.	20	20

J9100: common questions

Is J9100 a CPT code?: No. J9100 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 J9100?: CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 9 NDCs under J9100, for Cytarabine. The table on this page shows each one with its billing units per package.
What is the Medicare payment limit for J9100?: $0.853 per 100 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.
What is one billing unit of J9100?: One unit of J9100 is 100 mg, as stated in the code's descriptor. Units to report = dose given ÷ 100 mg. J-code billing units.

J9100 — Injection, cytarabine, 100 mg