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NDC Overview and Structure

Sep 10, 2025

Overview

The National Drug Code (NDC) is a unique numerical identifier used in the U.S. for prescription, over-the-counter, and insulin drug products. It consists of three segments and is required for regulatory, packaging, and billing purposes.

NDC Structure and Segments

  • The NDC is a 10- or 11-digit code with three segments: labeler, product, and package.
  • The first segment (labeler code) is assigned by the FDA to manufacturers, repackagers, or distributors.
  • The product code (second segment) identifies the drug’s specific strength, dosage form, and formulation.
  • The package code (third segment) indicates package sizes and types.
  • Labelers assign the product and package codes.

NDC Formatting and Examples

  • Common formats for the 10-digit NDC are 4-4-2, 5-3-2, or 5-4-1.
  • Example: Prozac (20 mg, 100-count) NDC is 0777-3105-02 (labeler: Dista Products Co.).
  • For billing, NDCs may be converted to an 11-digit 5-4-2 format by padding with leading zeros as needed.

Usage, Directory, and Accessibility

  • The NDC Directory contains information on all FDA-listed human drug products.
  • Only drugs with electronic listings (SPL) submitted to FDA are included since June 2011.
  • The FDA maintains a searchable online NDC database; NDCs are found on packaging and in labeling inserts.
  • Apps and pill identification tools also provide NDC lookup.

Exclusions and Non-Listed Products

  • Products not listed may be non-drugs, discontinued, or not fully registered electronically.
  • Compounded drugs by outsourcing facilities may be assigned NDCs but are not required to do so.

Billing and 11-Digit NDCs

  • Many payors and CMS require an 11-digit NDC (no hyphens or spaces), often in a 5-4-2 format.
  • Conversion from 10 to 11 digits involves adding zeros to the shortest code segment.
  • NDC use in billing varies by payor; vaccines may be excluded from NDC billing by some Medicaid plans.

Future Changes and 12-Digit NDC Proposal

  • The FDA anticipates running out of 5-digit labeler codes by around 2033.
  • A proposed rule would change the NDC to a standard 12-digit, 6-4-2 format to simplify processes.

Recommendations / Advice

  • Always verify NDC requirements with payors before claim submission, as rules can differ.
  • For drug identification or NDC questions, consult pharmacists or use FDA and Drugs.com resources.