NDC Numbers Explained: What Every Pharmacy Tech Should Know

What Is an NDC Number?

The National Drug Code (NDC) is a unique 10- or 11-digit identifier assigned to every drug product in the United States. It serves as a universal product identifier for human drugs in all practice settings. Pharmacy technicians use NDC numbers daily for dispensing verification, inventory management, and insurance billing.

The Three-Segment Format

The NDC is divided into three segments in a 5-4-2 format (or variations like 4-4-2 or 5-3-2):

• Labeler code (first segment) - Identifies the manufacturer, repackager, or distributor. Assigned by the FDA.
• Product code (second segment) - Identifies the specific drug product, including the drug name, strength, dosage form, and formulation. Assigned by the labeler.
• Package code (third segment) - Identifies the package size and type (e.g., bottle of 100, bottle of 500, unit dose). Assigned by the labeler.

Example Breakdown

NDC 00071-0155-23 for Lipitor (atorvastatin) 10mg:

• 00071 = Pfizer (labeler)
• 0155 = Atorvastatin 10mg tablets (product)
• 23 = Bottle of 90 tablets (package)

NDC in Pharmacy Practice

• Dispensing verification - Barcode scanning matches the NDC on the stock bottle to the prescription, confirming the correct drug was selected
• Insurance billing - Claims are submitted using the 11-digit NDC format. Different NDC numbers for the same drug (different manufacturers) may have different reimbursement rates
• Inventory management - NDC numbers track stock levels, reorder points, and expiration dates for specific products
• Recall identification - Drug recalls specify affected NDC numbers and lot numbers

11-Digit Billing Format

For insurance billing, NDC numbers are converted to a standard 11-digit format by adding leading zeros to segments as needed. The 5-4-2 format becomes the standard for electronic claims.

NDC knowledge is practical and testable. Review these concepts as part of your PTCE preparation.