Home › NDC Lookup › J-codes › J2291
J2291

J2291 – Inj, nafcillin (baxter) 20mg · NDC Crosswalk & Billing Units

HCPCS Level II J-code · Medicare Part B drug billing
J-code ● 2 NDCs crosswalked per 20 MG $0.148/unit ASP+6%

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

📋 J2291 summary

J2291 is a HCPCS Level II J-code used to bill nafcillin (baxter) 20mg, billed per 20 MG. The number of billing units to report depends on the dose administered and the NDC/package billed — use the calculator below.

Code J2291 Billing unit 20 MG Payment limit $0.148/unit NDC-Crosswalk 2 Quarter Q3 2026 RxCUI Atlas Trace the drug concept →

⚠ An NDC↔HCPCS crosswalk and a published payment limit do not guarantee payer coverage or payment. Always verify the current payer policy and claim format before billing.

🗂️ Key billing facts

HCPCS codeJ2291
DescriptorInj, nafcillin (baxter) 20mg
Billing unit20 MG
Payment limit / unit$0.148
Est. ASP / unit$0.140 est.
Mapped NDCs2
Data periodQ3 2026
Last updated2026-08-20

💊 About Nafcillin Injection DRUG GUIDE

NAFCILLIN Injection is used to treat infections caused by staphylococci — specifically strains that produce an enzyme called penicillinase, which makes them resistant to regular penicillin.

Susceptibility testing is performed to confirm the bacteria will respond to nafcillin before or shortly after starting treatment.Nafcillin may also be started right away when a resistant staph infection is strongly suspected, even before test results are available.

It should not be used for infections caused by bacteria that would respond to standard penicillin G, or for infections caused by non-staph organisms.

Read the full Nafcillin Injection drug guide →
Clinical overview from our editorial drug guide for Nafcillin Injection. For billing reference, see the sections above.

🧾 Billing & reimbursement HCPCS · CMS · EFF. Q3 2026

📅 Payment limits effective Q3 2026 — from the CMS Medicare Part B Payment Limit File (revised quarterly).
Medicare payment limit / unit
$0.148
Est. ASP / unit
$0.140 est.
Est. after 2% sequester
$0.145
HCPCS dosage
20 MG
The CMS payment limit is the Medicare Part B drug allowance (ASP + 6%, statutory). After the 2% federal sequester the effective payment is ≈ ASP + 4.3%; estimated ASP = payment limit ÷ 1.06. Source: CMS Medicare Part B Payment Limit File (quarterly), Q3 2026.

🧮 Dosing & billing-units calculator HCPCS UNITS

One billing unit of J2291 = 20 mg. Enter a regimen to convert dose → billing units and project a full course.
Billing units = dose ÷ HCPCS unit size. Most payers require whole units — round per the payer's policy. “Est. Medicare pay” uses the current payment limit. For single-dose vials, drug discarded after administration may be separately billable with modifier JW (JZ when none is discarded) where allowed. Always verify payer-specific rounding before billing.

🔁 NDCs that bill under J2291 WITH EST. MEDICARE PAY

2 NDCs map to J2291. Bill units = how many HCPCS units one package represents. Est. pay / pkg = payment limit ($0.148/unit) × that package's bill units.
NDC (11-digit)DrugLabelerPackageStrength Bill units Est. pay / pkg NADAC / unit StatusSource
00338-1017-41 Nafcillin Baxter — — 50 $7.40 — — CMS ASP
00338-1019-48 NAFCILLIN 2 g/100mL INJECTION, SOLUTION Baxter 100 mL in 1 BAG (0338-1019-48) 2 g/100mL 100 $14.80 — ● Active CMS + PDAC
NDC→HCPCS mappings come from the CMS ASP NDC-HCPCS crosswalk; additional DME MAC / DMEPOS mappings come from PDAC and are labeled separately. NADAC from CMS (weekly). “Status” reflects the product's marketing / obsolete flag in the NDC directory. Presence or absence here does not determine Medicare coverage. Linked NDCs open the full product page.

🗺️ Where J2291 is utilized

⏳
The geographic utilization map is building for this code — it aggregates millions of CMS Part B claim lines, then caches the result. Refresh in a moment; if it doesn’t appear, this code may have no reportable Part B utilization.

📊 What bills under J2291

J-codes are billing codes often used for drugs billed under the medical benefit. This connects the billing code to the NDC package records it covers, by ingredient and labeler.

NDC products by ingredient
NAFCILLIN 2
NDC products by labeler
Baxter Healthcare Corporation 2

🗃️ Data sources & freshness

Every figure on this page is computed from public datasets. Here's what each section draws on and how current it is.
HCPCS code & descriptor
CMS HCPCS Level II code file
Not available in current dataset
Payment limit & billing unit
CMS Medicare Part B ASP Pricing File (quarterly)
Q3 2026 · as of 2026-08-20
NDC ↔ HCPCS crosswalk
CMS ASP NDC-HCPCS crosswalk + DMEPDAC (PDAC)
2 NDCs mapped
NADAC acquisition cost
CMS National Average Drug Acquisition Cost (weekly)
Not available for mapped NDCs
Utilization & spend
CMS Part B Spending by Drug · PSPS · Physician & Other Practitioners
No reportable utilization
Figures are estimates for reference and may lag the source files. Always verify against the current CMS files and your payer's policy before submitting claims.

⚠️ Practical billing caveats

  • A crosswalk is not coverage. An NDC mapping or a published payment limit does not guarantee a payer will cover or pay this code. Check the specific plan's policy.
  • Units ≠ milligrams. Bill the number of HCPCS units (dose ÷ the code's unit size), not the milligram dose. Use the calculator above.
  • Discarded drug. For single-dose vials, drug discarded after administration may be separately billable with modifier JW (and JZ when nothing is discarded) where the payer allows.
  • Rounding & partial units. Many payers require whole units; round per the payer's policy, not automatically up.
  • The code can cover more than this drug. Some HCPCS codes span multiple products or strengths — confirm the exact code for the product administered.
  • Figures lag. ASP limits change quarterly and utilization data are released with a delay. Verify against the current CMS files before billing.

❓ J2291 billing FAQ

What is HCPCS code J2291?
J2291 is a HCPCS Level II J-code used to bill Inj, nafcillin (baxter) 20mg under Medicare Part B and most medical (not pharmacy) benefits.
What is the billing unit for J2291?
One unit of J2291 represents 20 MG. Report the number of units equal to the dose administered divided by 20 MG.
How many units of J2291 should I bill?
Divide the dose administered by the code's unit size (20 MG) to get the number of billing units, then round per your payer's policy. The calculator on this page converts a dose into billing units and projects a full course.
How much does Medicare pay for J2291?
The Medicare Part B payment limit is $0.148 per unit (Q3 2026), based on ASP + 6%. After the 2% sequester the effective payment is about $0.145 per unit. Payment limits are revised quarterly.
Which NDCs bill under J2291?
2 NDCs currently map to J2291 in the CMS ASP NDC-HCPCS crosswalk. See the NDC crosswalk table above for each product, package, billing units and estimated reimbursement.
Does a crosswalk mean J2291 is covered?
No. An NDC-to-HCPCS crosswalk and a published payment limit do not guarantee coverage or payment. Coverage depends on the payer, the diagnosis and the site of care — always verify the current policy before billing.
For professional billing reference only — verify against the current CMS files before submitting claims.