National Stock Number (NSN)

A National Stock Number (NSN) is a 13-digit standardized identification number assigned by the Defense Logistics Agency (DLA) to every item of supply stocked by the U.S. federal government, enabling consistent cataloging, ordering, and inventory management across all military branches and federal agencies.

What is a National Stock Number?

The NSN system is administered through the Federal Catalog System and governed by NATO Allied Committee 135 (AC/135) standards, meaning U.S. NSNs are compatible with those used by NATO allies. The 13-digit number consists of a 4-digit Federal Supply Classification (FSC) code that identifies the item's category, followed by a 2-digit National Codification Bureau (NCB) code identifying the assigning country (00 or 01 for the U.S.), and a 7-digit Non-Significant Number (NIIN) that uniquely identifies the item within its class.

When a contractor manufactures an item that the military intends to stock, DLA assigns an NSN through the Federal Catalog Program. This assignment triggers inclusion of the item in the Federal Catalog System, making it available for order by any authorized federal activity. Contractors supplying items with NSNs must package, mark, and label products according to MIL-STD-129 requirements and may be subject to quality assurance provisions under MIL-Q-9858 or AS9100 depending on the item class.

For contractors pursuing DLA distribution contracts, Federal Supply Schedule awards, or sole-source supply arrangements, knowing the NSN for the items they supply is essential. NSN data is publicly searchable through the Defense Logistics Information Service (DLIS) Product Data Retrieval System.

Why NSNs matter for government contractors

Cataloged items with assigned NSNs are eligible for automatic reorder through DLA's supply system, creating recurring demand without the contractor needing to win a new solicitation for each purchase. Suppliers who achieve NSN assignment for their products gain a stable, long-term revenue stream from government inventory replenishment programs.

Example

An electronics manufacturer produces a ruggedized power supply used in military field equipment. DLA assigns NSN 6130-01-432-1287. The power supply is now cataloged in the federal system, and any DoD activity needing the item can requisition it through DLA's supply chain. The manufacturer receives periodic orders without re-competing for each purchase, as long as their item remains the valid substitute on file and pricing remains within acceptable ranges.

Frequently Asked Questions

How does a manufacturer get an NSN assigned to its product?

The contractor submits a Federal Logistics Data (FED LOG) application to DLA, including technical data, drawings, specifications, and part identification information. DLA reviews the submission to determine whether the item duplicates an existing NSN or warrants a new assignment. The process typically takes 30 to 90 days.

Can the same item have multiple NSNs?

Ideally no, but in practice items manufactured by different companies to the same specification may have received separate NSNs over time. DLA actively works to rationalize and consolidate duplicative NSNs through its catalog standardization programs.

Do commercial items need NSNs?

Not automatically. Commercial items purchased on a one-time basis may not require NSN assignment. NSNs are most valuable for items that will be repetitively stocked and requisitioned through the military supply system. Commercial items procured under FAR Part 12 may bypass NSN requirements.

Where can contractors search for existing NSNs?

The Defense Logistics Information Service (DLIS) maintains the FED LOG database, which is searchable by part number, manufacturer code (CAGE code), item name, or NSN. The public PUBLOG database provides basic NSN lookup capability without registration.