6 NDC Numbers and Product Selection
Learn how NDC segments identify a drug product and package, how to match a product to a prescription, and how to interpret NDC formats.
NDC segments and patterns
A identifies a drug product and its trade package. In the current FDA-assigned format, it has 10 digits arranged in three hyphenated segments, with one of these patterns: 4-4-2, 5-3-2, or 5-4-1. Illustrative examples are 1234-5678-90, 12345-678-90, and 12345-6789-0; these are not product lookups.
The segments have distinct roles and are assigned as follows:
: Identifies the labeler, such as a manufacturer, repackager, relabeler, or distributor under whose name the product is marketed. The FDA assigns it.
: Identifies a particular product for that labeler, including its ingredient or ingredients, strength, dosage form, and formulation. The labeler assigns it.
: Identifies a particular package size and type for that product. The labeler assigns it.
Preserve the hyphens when interpreting a current 10-digit NDC. Segment lengths vary, so an unhyphenated number cannot always be split correctly just by counting from one end. The does not identify package size; that is the role of the .
Matching products to prescriptions
Select a product by comparing the prescription with the product’s labeling and an authoritative product record, rather than relying on a similar name or an NDC alone. Check each relevant product attribute:
Drug and ingredients: Match the prescribed drug. For a combination product, check every active ingredient.
Strength and concentration: Match the stated strength and units. For liquids, distinguish the amount per volume, such as mg per 5 mL, from the total volume in the bottle.
Dosage form and release characteristics: Match the required form, such as a tablet, capsule, or oral suspension, and the relevant release type, such as immediate-release or extended-release. Do not treat different forms or release types as interchangeable merely because the ingredient and strength look similar.
Route: Confirm that the product is intended for the prescribed route.
Package: Match the needed package size and type, such as a particular bottle volume or vial configuration. The identifies the marketed package; it is not the prescription quantity itself.
Product identity: Confirm the labeler and full NDC against the product container or listing. Generic and brand products, and products from different labelers, can have different NDCs even when their clinical attributes appear similar.
For example, a hypothetical prescription for a 250 mg/5 mL oral suspension does not match a 250 mg capsule, because the dosage form differs, or a 125 mg/5 mL suspension, because the concentration differs. After finding a product that matches the prescribed ingredient, strength, form, and route, check the and package description to select an appropriate container. A 100 mL bottle and a 150 mL bottle can have different package codes even when the product itself is the same.
Looking up and converting an NDC
Use the FDA National Drug Code Directory to check a product’s name, labeler, strength, dosage form, and listed package. Compare the listing with the actual product labeling and the prescription. The Directory is based on information submitted by labelers. Inclusion or assignment of an NDC does not mean FDA approval, verify every submitted detail, guarantee current availability, or establish insurance coverage.
The is a standardized derivative of the 10-digit FDA format. A leading zero is added to the appropriate segment to make the segments 5-4-2. The zero’s position depends on the original hyphenated pattern; do not simply add a zero at the beginning or end. Before converting an unhyphenated number, establish its correct segment pattern from a reliable product record.
NDC format transition
As of October 26, 2026, FDA-assigned NDCs remain 10 digits in the current variable-segment formats. FDA’s uniform 12-digit format is scheduled to take effect on March 7, 2033. This FDA 12-digit format is distinct from the .