What number is assigned by the manufacturer and placed on all prescription stock packages?

The National Drug Code (NDC) is the number assigned by the manufacturer and placed on all prescription stock packages. This unique identifier is a three-segment code that is integral to the identification of medications in the United States.

The first segment identifies the labeler or manufacturer, the second segment identifies the specific product, and the third segment indicates the package size and type. The NDC helps pharmacists and healthcare providers easily locate the correct medication, ensuring safe and efficient dispensing. It also plays a crucial role in inventory management, billing, and regulatory compliance within the pharmaceutical industry.

The other options do not fulfill this role: an order number is typically used for tracking orders but does not uniquely identify a drug; an ISBN is linked to books rather than pharmaceuticals; and "warehouse" refers to a storage location, not a specific identification number related to drug products.