What does an NDC stand for? Decoding the National Drug Code

October 8, 2025 •

3 min read

According to the U.S. Food and Drug Administration (FDA), every human drug product is assigned a unique, 3-segment, 10 or 11-digit number known as the National Drug Code (NDC). Understanding what does an NDC stand for is crucial for anyone involved in healthcare, from pharmacists to patients, as it serves as a universal product identifier across the U.S..

Quick Summary

The National Drug Code (NDC) is a unique, three-segment number assigned to human drugs in the U.S. to identify the labeler, product, and package size, facilitating proper tracking and billing.

Key Points

National Drug Code: NDC stands for National Drug Code, a unique identifier for human drugs in the U.S..
Three-Segment Structure: The NDC is a three-segment number that identifies the drug's labeler, product, and package size.
Billing Conversion: A 10-digit NDC from the package is often converted to an 11-digit format for insurance claims by adding a leading zero.
FDA's Role: The FDA assigns the labeler code and maintains the official NDC Directory, which is updated daily.
Universal Identifier: The NDC is a universal identifier crucial for accurate drug tracking, billing, and inventory management throughout the healthcare supply chain.
Future Format: The FDA has proposed a new 12-digit, uniform 6-4-2 format to prevent future code exhaustion.

Understanding the National Drug Code (NDC)

The National Drug Code (NDC) is more than just a series of numbers on a drug label; it's a standardized system that provides crucial information about a medication. Established by the Drug Listing Act of 1972, the NDC is a universal product identifier that helps regulate the drug supply chain by providing transparency and traceability. It is used by everyone from manufacturers and distributors to pharmacies and insurance providers, playing a fundamental role in product identification, reimbursement, and record-keeping.

The Three Segments of an NDC

An NDC is comprised of three distinct segments, each providing a specific piece of information about the drug. While the total number of digits can be 10 or 11, the structure remains consistent, with dashes separating the segments.

Segment 1: Labeler Code: The first segment identifies the specific firm that manufactures, repacks, or distributes the drug under its own name. This code is assigned by the FDA and can be 4, 5, or 6 digits long. A firm with multiple products will have a single, consistent labeler code across all its offerings.
Segment 2: Product Code: This segment identifies the specific strength, dosage form (e.g., tablet, capsule, liquid), and formulation of a drug. For example, a 20mg capsule and a 40mg capsule of the same drug will have different product codes. The labeler assigns this code, which is 3 or 4 digits long.
Segment 3: Package Code: The final segment identifies the specific package size and type. This differentiates between a bottle of 100 tablets versus a bottle of 50 tablets of the same drug. The labeler also assigns this code, which is 1 or 2 digits long.

For example, in the NDC 0777-3105-02 for Prozac, 0777 is the labeler code, 3105 is the product code, and 02 is the package code.

10-Digit vs. 11-Digit NDC: A Crucial Distinction

While the 10-digit NDC is the standard printed on drug packaging, an 11-digit version is required for insurance billing. This conversion ensures a uniform format for processing claims, particularly for government programs like Medicare and Medicaid. The 10-digit NDC appears in one of three possible formats, and a leading zero is added to the appropriate segment to convert it to the mandatory 5-4-2, 11-digit billing format.


10-Digit Format (on package)	10-Digit Segment Structure	How to Convert to 11-Digit	11-Digit Format (for billing)
`XXXX-XXXX-XX`	`4-4-2`	Add a leading '0' to the labeler code.	`0XXXX-XXXX-XX`
`XXXXX-XXX-XX`	`5-3-2`	Add a leading '0' to the product code.	`XXXXX-0XXX-XX`
`XXXXX-XXXX-X`	`5-4-1`	Add a leading '0' to the package code.	`XXXXX-XXXX-0X`

This conversion is a critical step in the claims process, and a mismatch or incorrect format can lead to a billing denial.

The Future of the NDC

Due to the increased pace of drug listings, the FDA has been working to address the potential exhaustion of available 10-digit NDC numbers. In 2022, the FDA proposed a rule for a single, uniform 12-digit NDC format, 6-4-2, to be adopted by all stakeholders. If finalized, this would simplify the current system and eliminate the need for manual conversion for billing purposes.

How NDCs are Used in Practice

NCDs serve as the backbone for numerous pharmaceutical operations:

Supply Chain Management: Manufacturers use NDCs for inventory tracking, production lots, and distribution logistics.
Pharmacy Operations: Pharmacists use NDCs to ensure they dispense the correct drug, dosage, and package size for a prescription. Electronic health record (EHR) systems use the code for scanning and verification.
Billing and Reimbursement: Insurance companies, including Medicare and Medicaid, require the 11-digit NDC on claim forms to accurately reimburse providers for the specific drug administered or dispensed.

Finding an NDC

Patients, healthcare providers, and researchers can find NDC numbers on the physical product labeling, including the packaging and package insert. The FDA also provides a searchable and updated daily National Drug Code Directory online. You can access it through the FDA's website for comprehensive information about listed drugs.

The Importance of the NDC

In conclusion, the National Drug Code is a vital tool that underpins the entire U.S. pharmaceutical system. By providing a standardized, unique identifier for every human drug, it enables a high degree of transparency and accuracy throughout the supply chain. From ensuring patients receive the right medication to streamlining the complex process of healthcare billing and reimbursement, a thorough understanding of what does an NDC stand for is fundamental to modern pharmacology and healthcare administration.

Visit the FDA's National Drug Code Directory for more information

Frequently Asked Questions

The primary purpose of an NDC is to serve as a universal product identifier for human drugs in the United States, providing transparency and ensuring accurate tracking from the manufacturer to the patient.

The U.S. Food and Drug Administration (FDA) assigns the first segment, the labeler code. The labeler, such as the manufacturer or distributor, assigns the second (product) and third (package) segments.

To convert a 10-digit NDC to the required 11-digit format for billing, you must add a leading zero to the segment that is short. For example, a 4-4-2 format becomes 0-4-4-2, a 5-3-2 becomes 5-0-3-2, and a 5-4-1 becomes 5-4-0-1 to achieve the 5-4-2 structure.

No, inclusion in the NDC directory does not equate to FDA approval. The directory contains information on all finished and unfinished drugs listed by manufacturers, which is a separate requirement from the FDA's approval process for a drug's safety and efficacy.

Yes, an NDC can be used to identify a specific drug. Each segment provides details about the manufacturer, the exact strength, dosage, and formulation, and the package size and type, making it a highly specific identifier.

The FDA has proposed a single, uniform 12-digit NDC format with a 6-4-2 segment structure to address the potential exhaustion of the current 10-digit code space.

You can use the official NDC Directory maintained by the FDA, which is available on their website and updated daily. It contains product listing data submitted by drug establishments.