No. J9319 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 is the Medicare payment limit for J9319?

$32.343 per 0.1 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 J9319?

One unit of J9319 is 0.1 mg, as stated in the code's descriptor. Units to report = dose given ÷ 0.1 mg.

J9319 J-Code: Istodax lyophilized (romidepsin)

In short

J9319 is the HCPCS Level II code for injection, romidepsin, lyophilized, 0.1 mg. CMS assigns NDCs for Istodax lyophilized and Romidepsin lyophilized to it. One billing unit is 0.1 mg. The Medicare Part B payment limit is $32.343 per unit (October 1, 2026 through December 31, 2026).

Code

CMS HCPCS file

HCPCS codeJ9319

Billing unit0.1 mg

Descriptor: Injection, romidepsin, lyophilized, 0.1 mg
Short descriptor: Inj romidepsin lyophil 0.1mg
Code set: HCPCS Level II, maintained by CMS
Effective: Oct 1, 2021

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$32.343

Per0.1 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 ÷ 0.1 mg. For example, 10 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 = 0.1 mg)

Modifier

NDC (11-digit)

NDC unit qualifier

NDC quantity

Enter the dose given to build the claim line.

NDCs billed under J9319

CMS’s ASP NDC–HCPCS crosswalk (effective October 1, 2026 through December 31, 2026) assigns 2 NDCs to J9319 for Istodax lyophilized and Romidepsin lyophilized. Billing units per package are CMS’s figures for this code’s unit.

NDCs assigned to J9319 in the CMS ASP crosswalk
Drug	NDC (11-digit)	Labeler	Package	Billing units per package
Istodax lyophilized	59572-0984-01	Celgene Corporation	1	100
Romidepsin lyophilized	63323-0926-88	FreseniUS Kabi USA, LLC	1	100

J9319: common questions

Is J9319 a CPT code?: No. J9319 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 J9319?: CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 2 NDCs under J9319, for Istodax lyophilized and Romidepsin lyophilized. The table on this page shows each one with its billing units per package.
What is the Medicare payment limit for J9319?: $32.343 per 0.1 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 J9319?: One unit of J9319 is 0.1 mg, as stated in the code's descriptor. Units to report = dose given ÷ 0.1 mg. J-code billing units.

J9319 — Injection, romidepsin, lyophilized, 0.1 mg