Finding NDC for J Code

Yes. CMS publishes the official NDC-HCPCS Crosswalk every quarter with the Medicare Part B Drug Payment Limit File (the ASP pricing files). CMS describes it as the file that "links each NDC to its associated HCPCS code." There are other CMS crosswalks, but CMS says "only the NDC-HCPCS crosswalk file listed on the Medicare Part B ASP website should be referenced for payment limits" (CMS fact sheet, June 2026, p. 2).

Approach: None of the datasets I can search has an NDC-to-HCPCS mapping. They do have the FDA NDC Directory and CMS Part B spending and NADAC pricing data. So I used CMS's ASP pricing files page and CMS's fact sheet on the payment limit file.

Where to find it (CMS ASP Pricing Files page)

• Current file: October 2026 NDC-HCPCS Crosswalk, posted 09/17/2026.
• Vaccines: separate 2026-2027 NDC-HCPCS Crosswalk for Seasonal Vaccines, posted 08/27/2026.
• Earlier 2026 files: July 2026 (06/17/2026), April 2026 (03/30/2026) and January 2026 (03/30/2026).
• Archive: quarterly files go back to 2005.

What it is and isn't (fact sheet, pp. 3-4)

• It doesn't list every NDC. It is "not meant to be a comprehensive listing of all NDCs that could be billed and paid for under Medicare Part B." It also says nothing about whether a product is covered. It mainly holds NDCs that were actively marketed and sold during the sales quarter.
• It changes every quarter.
  • Mappings are added when new HCPCS codes or NDC-HCPCS mappings are reported.
  • Products are removed when they are discontinued, recalled, no longer payable under Part B, or inactive for six quarters.
• A missing NDC can still be paid. The local Medicare Administrative Contractor (MAC) may still process the claim under the Medicare Claims Processing Manual, Pub. 100-04, Ch. 17, §20.1.2.
• Some settings use different files, and they aren't interchangeable with this one:
  • Hospital outpatient departments use the Outpatient Prospective Payment System (OPPS) Addendum A and B updates.
  • DME suppliers use the separate DME NDC-HCPCS crosswalk.
• Questions: sec303aspdata@cms.hhs.gov.

If you give me a specific NDC from the crosswalk, I can look it up in the FDA NDC Directory for labeler, package and marketing status.

You put the NDC on the same claim line as the drug's HCPCS code (the J-code). Enter the qualifier N4, then the 11-digit NDC, then a unit-of-measure qualifier (UN, F2, GR or ML) and the NDC quantity. The J-code and its HCPCS units still go in the normal procedure and units fields.

Approach: The datasets I can search hold drug, pricing and NDC registries but no claim-form billing instructions. So I used CMS's Medicare Claims Processing Manual (Pub. 100-04, Ch. 26) and Oregon Medicaid's billing guide for physician-administered drugs.

Paper professional claim (CMS-1500, item 24) (CMS Pub. 100-04, Ch. 26, §10.4, p. 16)

• Each of the six service lines has a shaded top half for extra information. The NDC goes in the shaded half of the drug's line.
• Positions 01-13: N4 followed immediately by the 11-digit NDC, e.g. N499999999999.
• Positions 17-24: the unit qualifier followed by the quantity, e.g. UN2 or F2999999. There are six characters for the quantity; start at the left and fill any unused positions with spaces.
• Item 24D: the HCPCS code (J-code) and any modifiers. Item 24G: the HCPCS units.
• CMS frames this as the method "when required to submit NDC drug and quantity information for Medicaid rebates."
• Oregon Medicaid says to put a space after N4 on the CMS-1500 (Oregon HSD, p. 12). That differs from the CMS example above, so follow your payer's own instructions.

Electronic claims (837P and 837I) (Oregon HSD, p. 20)

• 837P: loop 2400 SV101-1 = HC, and SV101-2 = the HCPCS drug code.
• 837P and 837I: the NDC goes in loop 2410 LIN03, and the unit of measure goes in the CTP segment of loop 2410.

Paper institutional claim (UB-04): Oregon says to enter the same items as on the CMS-1500 (N4, 11-digit NDC, unit qualifier, quantity) (p. 12). The sources I opened don't say which UB-04 field to use.

Formatting rules (Oregon HSD, pp. 10-19)

• Which NDC: the one on the package the dose actually came from.
• Converting 10 digits to 11 (5-4-2): add a leading zero to the short segment.
  • 5678-0123-01 → 05678-0123-01
  • 05678-123-01 → 05678-0123-01
  • 05678-0123-1 → 05678-0123-01
• Unit qualifiers:
  • GR: creams, ointments, powders.
  • ML: prefilled syringes and unit-dose liquids.
  • UN: powder vials that need reconstituting, and tablets or capsules.
  • F2: international units, e.g. Factor VIII.
• Quantity:
  • No decimal for whole numbers.
  • Fractions take a decimal with a leading zero (0.5).
  • No commas.
  • CMS-1500 allows up to 8 digits before the decimal and 3 after. On the UB-04, fractions are limited to 3 decimal places.
• HCPCS units and NDC quantity usually differ. For example, 4 mg of Zofran IV from NDC 00173-0442-02 (2 mg/mL) is billed as J2405 × 4 units with NDC quantity ML2.
• Two package sizes for one dose: bill one line per NDC with the same J-code. For example, Aranesp 125 mcg is billed as J0881 × 25 units with ML0.42, plus J0881 × 100 units with ML0.5.
• Multi-dose vial: bill only what was given. Single-dose vial: bill the whole vial.
• Unlisted drug codes (e.g. J3490, J3590, J9999): bill at acquisition cost, and on Medicare claims put the drug name and dose in item 19 (CMS Ch. 26, p. 12).
• 340B drugs: Oregon also requires modifier UD on the HCPCS code and a charge no higher than acquisition cost (p. 23).

Medicaid programs set their own rules. Oregon, for example, denies physician-administered drug claims without an NDC but exempts immunizations, vitamins and oral nutritional supplements (p. 8). Commercial payers also publish their own NDC billing rules.

If you give me the NDC you plan to bill, I can check its package description and marketing status in the FDA NDC Directory. That will help you choose the unit qualifier and quantity.