National Drug Code (NDC)

Key facts

Assigned under

FDA drug listing rules, 21 CFR Part 207

Format

10 digits in three segments: labeler, product, package

Segment layouts

4-4-2, 5-3-2 or 5-4-1

Billing format

11 digits (5-4-2), padded with a leading zero

Published in

FDA National Drug Code Directory

What is a National Drug Code?

Every drug that a company manufactures, repackages or relabels for commercial distribution in the United States must be listed with the Food and Drug Administration (FDA), and each listed package receives a National Drug Code. The code works like a product barcode for medicines: one NDC points to one labeler, one product formulation and one package configuration.

NDCs cover prescription drugs, over-the-counter drugs and many biologics. Two bottles of the same drug in different pack sizes carry different NDCs, and so does the same molecule sold by two different labelers.

An NDC is an identifier, not a stamp of approval. Listing a product and publishing its NDC does not mean the FDA has approved the drug.

How an NDC is structured

The 10 digits are split into three segments separated by hyphens:

• Labeler code: assigned by the FDA to the firm that manufactures, repackages or distributes the drug.
• Product code: assigned by the labeler to identify a specific strength, dosage form and formulation.
• Package code: assigned by the labeler to identify the package size and type.

10-digit vs 11-digit NDCs

Because the labeler code can be four or five digits long, a 10-digit NDC appears in one of three layouts: 4-4-2, 5-3-2 or 5-4-1. Pharmacy and medical claims typically use an 11-digit NDC in a fixed 5-4-2 layout, created by adding a leading zero to whichever segment is short: 1234-5678-90 becomes 01234-5678-90, and 12345-678-90 becomes 12345-0678-90.

The FDA has proposed moving to a single, uniform 12-digit NDC format as labeler codes run out. Until a final rule takes effect, datasets mix the 10-digit FDA format with the 11-digit billing format, so normalizing to one layout is the first step before joining sources.

Why the NDC matters

The NDC is the join key that connects most U.S. drug data:

• Pricing benchmarks such as NADAC and Medicaid drug rebate files are reported at the NDC level.
• Pharmacy claims record the exact NDC dispensed, so analysts can measure volume by product and package.
• Recall and shortage notices typically identify affected products by NDC, so buyers can check inventory against them.
• Structured product labeling files list the NDCs each drug label covers.