No. J0841 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 J0841?

CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 1 NDC under J0841, for Anavip. The table on this page shows each one with its billing units per package.

What is the Medicare payment limit for J0841?

$1,084.909 per 120 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 J0841?

One unit of J0841 is 120 mg, as stated in the code's descriptor. Units to report = dose given ÷ 120 mg.

J0841 J-Code: Anavip (crotalidae immune f2)

In short

J0841 is the HCPCS Level II code for injection, crotalidae immune f(ab')2 (equine), 120 mg. CMS assigns NDCs for Anavip to it. One billing unit is 120 mg. The Medicare Part B payment limit is $1,084.909 per unit (October 1, 2026 through December 31, 2026).

Code

CMS HCPCS file

HCPCS codeJ0841

Billing unit120 mg

Descriptor: Injection, crotalidae immune f(ab')2 (equine), 120 mg
Short descriptor: Inj crotalidae im f(ab')2 eq
Code set: HCPCS Level II, maintained by CMS
Effective: Jan 1, 2019

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$1,084.909

Per120 mg

Coinsurance20%

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

Units and claim line

Units = dose given ÷ 120 mg. For example, 12000 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 = 120 mg)

Modifier

NDC (11-digit)

NDC unit qualifier

NDC quantity

Enter the dose given to build the claim line.

NDCs billed under J0841

CMS’s ASP NDC–HCPCS crosswalk (effective October 1, 2026 through December 31, 2026) assigns 1 NDC to J0841 for Anavip. Billing units per package are CMS’s figures for this code’s unit.

NDCs assigned to J0841 in the CMS ASP crosswalk
Drug	NDC (11-digit)	Labeler	Package	Billing units per package
Anavip	66621-0790-02	Rare Disease Therapeutics, Inc.	1	1

J0841: common questions

Is J0841 a CPT code?: No. J0841 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 J0841?: CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 1 NDC under J0841, for Anavip. The table on this page shows each one with its billing units per package.
What is the Medicare payment limit for J0841?: $1,084.909 per 120 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 J0841?: One unit of J0841 is 120 mg, as stated in the code's descriptor. Units to report = dose given ÷ 120 mg. J-code billing units.

J0841 — Injection, crotalidae immune f(ab')2 (equine), 120 mg