No. J0584 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 J0584?

CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 3 NDCs under J0584, for Crysvita. The table on this page shows each one with its billing units per package.

What is the Medicare payment limit for J0584?

$516.85 per 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.

J0584 J-Code: Crysvita (burosumab-twza 1 mg)

In short

J0584 is the HCPCS Level II code for injection, burosumab-twza 1 mg. CMS assigns NDCs for Crysvita to it. The Medicare Part B payment limit is $516.85 per unit (October 1, 2026 through December 31, 2026).

Code

CMS HCPCS file

HCPCS codeJ0584

Billing unitSee descriptor

Descriptor: Injection, burosumab-twza 1 mg
Short descriptor: Injection, burosumab-twza 1m
Code set: HCPCS Level II, maintained by CMS
Effective: Jan 1, 2019

Medicare Part B payment limit

CMS ASP file

Payment limit per unit$516.85

Per1 mg

Coinsurance18.18%

Effective October 1, 2026 through December 31, 2026. Payment allowance limits subject to the ASP methodology are based on 2Q26 ASP data. CMS note: Inflation-adjusted coinsurance. 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 J0584

CMS’s ASP NDC–HCPCS crosswalk (effective October 1, 2026 through December 31, 2026) assigns 3 NDCs to J0584 for Crysvita. Billing units per package are CMS’s figures for this code’s unit.

NDCs assigned to J0584 in the CMS ASP crosswalk
Drug	NDC (11-digit)	Labeler	Package	Billing units per package
Crysvita	42747-0102-01	Kyowa Kirin, Inc.	1	10
Crysvita	42747-0203-01	Kyowa Kirin, Inc.	1	20
Crysvita	42747-0304-01	Kyowa Kirin, Inc.	1	30

J0584: common questions

Is J0584 a CPT code?: No. J0584 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 J0584?: CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 3 NDCs under J0584, for Crysvita. The table on this page shows each one with its billing units per package.
What is the Medicare payment limit for J0584?: $516.85 per 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.

J0584 — Injection, burosumab-twza 1 mg