In an NDC, what do the middle four numbers identify?

• A. The first five numbers identify the drug manufacturer.
• B. The middle four numbers identify the drug product.
• C. The last two numbers identify the packaging.
• D. The entire 11-digit sequence identifies the substance.

Answer: (B)

The middle four digits are the product code that identifies the specific drug product within a manufacturer's catalog. In the NDC’s 5-4-2 structure, the first five digits denote the labeler (manufacturer), the middle four define the product (drug name, strength, and dosage form), and the last two indicate the packaging. So, the middle portion uniquely distinguishes which drug product is being referenced, separate from who made it or how it’s packaged. The full 11-digit code then identifies a particular package of that product from that manufacturer.