A National Stock Number is an official label applied to an item of supply that is repeatedly procured, stocked, stored, issued, and used throughout the federal supply system. It is a unique item identifying series of numbers. When a NSN is assigned to an item of supply, data is assembled to describe the item. Some data elements include information such as an item name, manufacturer's part number, unit price, and physical and performance characteristics. NSN's are an essential part of the military's logistics supply chain used in managing, moving, storing, and disposing of material.

NSN's are used to identify and manage nearly every imaginable item, from aircraft parts to light bulbs. The use of NSN's facilitates the standardization of item names, supply language, characteristics and management data and aids in reducing duplicate items in the federal inventory. It also helps to standardize the military requirements for testing and evaluation of potential items of supply, as well as identifying potential duplicate items.

The United States government, the North Atlantic Treaty Organization (NATO), and many governments officially recognize the NSN around the world. Federal agencies, including the Department of Defense (DOD), use the NSN to buy and manage billions of dollars worth of supplies yearly. Currently, there are over 7 million NSN's in the federal supply system.

During World War II, it was common to find different names applied to a single item of supply used by each military service. That made it difficult for the Services to locate supplies and, in most cases, impossible to share items of supply. This resulted in an item depletion situation for one service and item surplus situation for another due to different naming conventions.

To illustrate this complex issue one only needs to consider what the name of the following item is. Is it a washer, a spacer or a shim? The correct name for this item is WASHER, FLAT.

This is one example of why it is so important to establish a common name and description for a single item of supply. If each of the services called this washer by a different name, there would be no way to identify and move assets from one service to another when needed. Additionally, it was determined to be essential that DOD describe all like items the same, with the same characteristics to facilitate comparison of items and avoid proliferation of like items in the DOD inventory. Even today, commercial entities continue to justify and reinforce the need for a standardized national stock numbering system. Manufacturers, as in the case of the preceding washer, use a variety of item names for identical parts. Cataloging these items with different item names creates inconsistencies in the various logistics management systems, making it difficult to identify, separate and control inventory of items.

Manufacturers use many different commercial part-numbering conventions. For example, manufacturers may refer to their items of supply using various descriptors like a Universal Product Code (UPC), a National Drug Code, and/or a Universal Standard Products and Services Classification Code (UNSPSC) as part of the item description. The NSN alleviates manufacturers from using various languages to describe items of supply by standardizing naming conventions and logistics management data.

Structure of the National Stock Number (NSN)

The configuration of the NSN is a 13-digit number, as the examples above show. It is composed of these overlapping sub-groups:

• Federal Supply Group (FSG): Positions 1-2
• Federal Supply Class (FSC): Positions 1-4
• Country Code: Positions 5-6
• National Item Identification Number (NIIN): Positions 5-13
• Serial Number: Positions 7-13

The first two digit positions identify the Federal Supply Group (FSG), the broad category in which the item belongs.

The FSG is followed by two additional positions, which together with the FSG form the four positions Federal Supply Class (FSC). The FSC narrows the category down to something more specific.

The last 9 positions (e.g. 00-000-0000) are the National Item Identification Number (NIIN) and identify the specific item. The first two positions of the NIIN identify the NATO Country Code for the country making the number assignment. The codes 00 and 01 are used by the United States. The last seven digits of the NIIN are the item serial number. The serial number does not follow an assignment pattern as the FSG, FSC and country code do; it is merely a number chosen for the item.

When the FSN was converted to the NSN in 1975, existing FSN's were typically changed over by simply adding "00" between the FSC and the serial number. For example, "First Aid Kit, General Purpose, Rigid Case", FSN 6545-922-1200, was changed to NSN 6545-00-922-1200.

If an item is issued in different sizes, each size will have its own NIIN. Sometimes all the sizes follow a logical pattern, sometimes not. When items from different manufacturers perform the same function, have the same characteristics, and are the same size, a single NSN is assigned. For example, all flashlight standard D batteries have the same NSN regardless of supplier.

Because the FSC is assigned based on end use, it is possible for the same item to be in more than one FSC. For example, a cleaning compound could be assigned FSC 6850 when used for general purpose cleaning, but the same chemical composition would be assigned FSC 6750 when used as a photographic cleaner. In each case, the NIIN would be different.

Who Uses National Stock Numbers?

Domestic and foreign governments, all the military services and various federal and civil agencies use the NSN. The United States government, the North Atlantic Treaty Organization (NATO), and many other governments around the world officially recognize the NSN. The NSN affords the opportunity for greater cross-servicing potential and facilitates operations that involve many military services from many nations.

-Federal Agencies

Many federal agencies, including the Department of Defense (DOD), use the NSN to buy and manage billions of dollars worth of supplies yearly. The Defense Logistics Agency (DLA) establishes how each DLA-Managed NSN will be stocked, stored and issued to the Services. DLA evaluates usage demands to determine required quantities of NSN's. The NSN is the foundation for logistics coordination between the services and government agencies.

-Military Services

The practice of using a single language of supply like the NSN is increasingly important as it promotes coordination between the Services, readiness, and availability to all users. The NSN is also critical to the effective integration of the services in joint military endeavors. The NSN enables military services to access the same information and identify like items of supply. Mechanics, technical inspectors, maintenance and other supply personnel can review NSN data in the FLIS to locate information on all parts needed to maintain and support weapon systems.

The use of NSN's provides logistics managers, procurement personnel, operations planners, and industrial base assessment personnel with a standard method of identifying and tracking items of supply in-storage, in-process, in-transit and in-theater.

What is the Value of a National Stock Number?

• Reduces downtime by enabling procurement personnel to quickly
• Identify, locate, and order parts or supplies
• Accounts for existing inventory
• Identifies shelf life of an item of supply
• Maximizes use of available spares by identifying items of supply that are interchangeable or substitutable
• Provides pricing information, which is valuable when negotiating contracts and managing military budgets
• Improves cycle times for design, manufacture, and repair processes while extending weapon system life cycles
• Centralizes item information on all items managed within DOD
• Provides built-in protection for safeguarding proprietary information and limiting access to only those entities requiring such information
• Records multiple manufacturers on NSN's which increases supportability
• Aids in identifying duplicate items of supply

Perhaps the most significant and far-reaching benefit of the NSN is that it provides life cycle management of items of supply, from requisition to acquisition to maintenance to disposal.

Information obtained from the Defense Logistics Agency.