What Is an NDC Number and How Foreign Drug Manufacturers Obtain One

The National Drug Code — NDC — is the unique identifier assigned to every drug product marketed in the United States. It appears on product labels, in FDA databases, in pharmacy dispensing systems, and in the import documentation that customs and the FDA use to verify each incoming shipment. Without a valid NDC on the label and in the FDA's drug listing system, a drug product cannot legally be sold in the US market, and a shipment of unlisted drug products can be refused at entry. For foreign drug manufacturers entering the US market, understanding what an NDC is and how it is obtained is as fundamental as understanding the registration requirement itself.

The structure of an NDC number

An NDC number is an 11-digit numeric code divided into three segments: a labeler code, a product code, and a package code. The labeler code — typically five digits — identifies the firm that manufactures, repacks, or distributes the drug. The product code — typically four digits — identifies the specific strength, dosage form, and formulation of the drug. The package code — typically two digits — identifies the packaging type and size. The FDA assigns the labeler code. The manufacturer assigns the product and package codes within the labeler code space the FDA has allocated. A single labeler code can accommodate thousands of distinct NDC numbers for different products and package sizes.

How the labeler code is assigned and what it requires

To obtain a labeler code — and therefore the ability to assign NDC numbers to products — a firm must be registered as a drug establishment with the FDA. The labeler code is assigned to the registered establishment as part of the drug registration process. A foreign manufacturer that has not registered its establishment cannot obtain a labeler code, and without a labeler code there is no valid NDC to put on a drug product label. The sequence is fixed: drug establishment registration comes first, the labeler code follows, and NDC assignment follows from there. This is also why a change in the manufacturing facility — for example, shifting production from one plant to another — requires updating the establishment registration, which may require a new labeler code and therefore new NDC numbers.

Drug listing and what connects it to the NDC

Once a labeler code is obtained, the manufacturer must submit a drug listing for each product under that code. Drug listing is the process by which the specific drug products — identified by NDC, proprietary name, active ingredients, dosage form, route of administration, and marketing status — are entered into the FDA's Drug Registration and Listing System. The listing submission is what makes an NDC number officially associated with a specific product in the FDA's records. A drug product whose NDC appears on a label but has not been listed is non-compliant. The FDA's drug listing database is publicly accessible, and US pharmacies, distributors, and importers routinely check it to verify that products are properly registered before purchase or import.

Common NDC problems foreign manufacturers encounter

Foreign manufacturers new to the US drug market commonly encounter three NDC problems. First, they apply NDC numbers to products before the drug establishment registration is complete and the labeler code is officially issued — the codes used are invalid. Second, they list a product under one NDC but ship it with a different package size or formulation that would require a different product or package code — creating a mismatch between the physical product and the FDA record. Third, they fail to update the drug listing when a product is reformulated, repackaged, or discontinued — creating a record in the FDA system that no longer matches what is actually being sold. Each of these problems can lead to import refusals, FDA notices of violation, or rejection by US distribution channels.

How FDABridge manages NDC and drug listing for foreign manufacturers

FDABridge handles drug establishment registration, labeler code coordination, drug listing submissions, and NDC assignment for foreign drug manufacturers entering the US market. We maintain the drug listing records in the FDA system and track all update obligations when product details change. Visit fdabridge.com/drug for our drug registration services or fdabridge.com/apply/drug to start the process.