What is NDC in simple terms? A guide to the National Drug Code

October 8, 2025 •

5 min read

Every human drug product in the United States must have a unique identifier called the National Drug Code (NDC), a standard established by the FDA. This system helps track and manage medications throughout the supply chain. This article explains what is NDC in simple terms and what each segment of the code means for consumers.

Quick Summary

The National Drug Code (NDC) is a unique, three-segment number on drug packaging that identifies the manufacturer, product, and package size. It is crucial for drug tracking, patient safety, and healthcare billing processes, ensuring transparent and accurate medication management.

Key Points

Universal Drug Identifier: The NDC is a unique, three-segment number used in the U.S. to identify every human drug product.
Three Key Segments: The code is broken down into three parts: the labeler code (manufacturer), the product code (strength/formulation), and the package code (size/type).
FDA Assignment: The FDA assigns the labeler code, while the manufacturer assigns the product and package codes.
Billing Format: While packages show a 10-digit NDC, an 11-digit format (5-4-2) is required for billing and insurance claims.
Ensures Patient Safety: The NDC helps prevent medication errors by standardizing drug identification, a key factor for dispensing and administration.
Supports Healthcare Operations: NDCs are essential for drug tracking, recalls, inventory management, and accurate billing throughout the healthcare supply chain.
Not an Rx Number: An NDC is a product identifier, different from the prescription (Rx) number, which identifies a specific prescription fill.

The National Drug Code, or NDC, is a unique identifier assigned to every human drug product in the United States. You can find this code printed on the label of both prescription and over-the-counter medications. Think of it as a universal barcode for pharmaceuticals, providing a standardized way to identify and track drugs from the manufacturer all the way to the patient. While the code can look like a random set of numbers, it actually contains a wealth of information about the medication it represents.

What is NDC: The breakdown of the code

The NDC is a numerical code that can be either 10 or 11 digits long, separated into three distinct segments by hyphens. Each segment identifies a specific piece of information about the drug. Understanding these parts makes the code much less intimidating and highlights its purpose in ensuring medication safety and accuracy.

The three segments of an NDC

Segment 1: The Labeler Code. The first set of digits identifies the manufacturer, repackager, or distributor of the drug. The Food and Drug Administration (FDA) assigns this portion of the code. This is important because different companies might produce identical drugs, but each will have its own unique labeler code.
Segment 2: The Product Code. The middle set of numbers identifies the specific drug product itself. This includes details like its active ingredients, strength, and dosage form (e.g., tablet, capsule, liquid). A single manufacturer will assign a different product code for different strengths or formulations of the same drug.
Segment 3: The Package Code. The final set of numbers identifies the specific package size and type. For example, a 100-count bottle of tablets will have a different package code than a 30-count bottle of the exact same tablets. This ensures that inventory and billing are accurate down to the exact size of the product purchased.

How is an NDC assigned and used?

The process begins with the FDA assigning a labeler code to a company. The company then assigns its own product and package codes and registers them with the FDA. The entire code is then included in the FDA's NDC Directory, a database updated daily to track all listed drugs.

The 10-digit vs. 11-digit NDC: A billing difference

While the code on your medication package may be 10 digits long (in a 4-4-2, 5-3-2, or 5-4-1 format), it needs to be an 11-digit code for billing purposes. Healthcare providers, insurers, and government programs like Medicare require this standard 11-digit format (5-4-2) for accurate claims processing. To convert a 10-digit code, a leading zero is simply added to the appropriate segment to ensure the 5-4-2 structure.

For example:

A 10-digit code of 9999-999-99 becomes 99999-0999-99 for billing.
A 10-digit code of 99999-9999-9 becomes 99999-9999-09 for billing.

Comparison: NDC vs. Prescription (Rx) Number

It's easy to confuse the NDC with another number found on your medication label: the prescription number. While both are critical identifiers, they serve very different purposes. The NDC is a universal product identifier, while the Rx number is a unique transaction identifier specific to your prescription fill.


Feature	National Drug Code (NDC)	Prescription (Rx) Number
Purpose	To identify the drug product itself (manufacturer, strength, form, package size).	To identify a specific dispensing event for a particular patient.
Who assigns it?	FDA (labeler code) and manufacturer (product/package code).	The pharmacy at the time of dispensing.
Uniqueness	A universal code for all units of a specific drug product in the US.	Unique to each individual prescription fill, even for the same patient and drug.
Where is it found?	On the drug's packaging and often on the prescription label.	On the patient's prescription label.

The importance of the NDC

The NDC system is a cornerstone of modern pharmacy and healthcare, providing transparency and accuracy that benefits every part of the medication supply chain.

Ensuring Patient Safety: By standardizing drug identification, the NDC helps reduce the risk of medication errors. Pharmacists and healthcare providers can use the code to verify that the correct drug, strength, and dosage form are being prescribed and dispensed. In a hospital setting, NDCs can be scanned to cross-reference against a patient's medical record, further minimizing errors.
Facilitating Drug Tracking: For the FDA and pharmaceutical companies, the NDC is a powerful tool for tracking drugs. It helps monitor drug distribution, identify counterfeit products, and manage drug recalls quickly and efficiently. If a product is recalled, the NDC provides a specific, universal way to identify and pull the affected items from shelves.
Simplifying Billing and Reimbursement: The standardized 11-digit NDC is a requirement for submitting claims to insurance companies, including federal programs like Medicare and Medicaid. This ensures that payers are billed accurately for the exact medication that was administered or dispensed.
Improving Pharmacy and Hospital Operations: Within a pharmacy or hospital, the NDC streamlines inventory management and ordering. Staff can scan barcodes containing the NDC to track stock levels, reorder products, and manage expiring medications, leading to better operational efficiency and reduced waste.

The future of the NDC

The FDA has proposed a rule to standardize the NDC to a uniform 12-digit, 6-4-2 format in the future. This change is designed to resolve inconsistencies between the 10-digit format on labels and the 11-digit format used for billing, creating a single, consistent identifier for all purposes. For consumers, this will likely mean a more streamlined and accurate system, though the core purpose of the NDC will remain the same.

Conclusion

In simple terms, the National Drug Code (NDC) is a vital, three-part number that serves as the universal product identifier for all drugs in the U.S. By detailing the manufacturer, the specific medication, and its package size, the NDC ensures transparency and accuracy throughout the entire healthcare system. For consumers, understanding this code offers a deeper insight into the standardized process that helps protect their safety and ensures the correct medication is dispensed and billed every time. It's a small but powerful set of numbers that plays a huge role in modern pharmacology and patient care.

Frequently Asked Questions

The National Drug Code (NDC) is usually printed on the medication's container, such as the bottle, tube, or vial, as a 10-digit number broken into three segments by hyphens.

No, the NDC is not the same as a prescription number. The NDC is a universal product identifier for the drug itself, while the prescription (Rx) number is a unique number assigned by the pharmacy for a specific prescription fill.

For billing purposes, many payers, including Medicare and private insurers, require a standardized 11-digit format (5-4-2) for the NDC. The 10-digit code found on the packaging is converted by adding a leading zero to the appropriate segment.

Every human drug product in the United States, including both prescription and over-the-counter medications, is required to have a unique NDC. However, animal drugs and some unapproved drugs may not be included.

While both are identifiers, the NDC is a government-mandated code specifically for human drug products, detailing the manufacturer, product, and packaging. A UPC (Universal Product Code) is a more general retail product barcode.

No. The presence of an NDC number on a product does not mean it has been FDA-approved. It simply indicates that the drug has been listed with the FDA.

The NDC provides a precise and universal way to identify and track specific drug products. This allows regulatory bodies and healthcare providers to quickly identify, locate, and remove affected products from the market during a recall.