NSN Number Lookup: How to Look Up Any NSN (2026 Guide)

An NSN number lookup finds the official record behind a 13-digit National Stock Number so you can identify the item, learn who supplies it, and see the part numbers that cross-reference to it. Every NSN breaks into three pieces: a 4-digit Federal Supply Class, a 2-digit country code, and a 7-digit item number. You can run an NSN lookup for free on DLA's public logistics data, or use WebFLIS with a CAC. This guide shows you the exact tools, the steps, and how to read the results like a buyer.

What Is an NSN Number?

An NSN is a National Stock Number. It is the 13-digit code the Department of Defense assigns to an item it buys over and over. Screws, gaskets, bearings, valves, switches, cable assemblies — if the military buys it repeatedly, it gets an NSN.

The NSN is managed by the Defense Logistics Agency (DLA). DLA runs most of the military's supply chain and catalogs millions of items. Each NSN points to one item and one item only. Two parts that look alike but are not interchangeable get two different NSNs.

That is the whole point. The NSN replaces a pile of manufacturer names and part numbers with a single number any buyer, warehouse, or depot in the world can read. When a unit in Germany needs a fuel pump, it does not describe the pump. It orders the NSN.

The NSN is also called a National/NATO Stock Number. The United States and its NATO allies share the same numbering system, so one number works across many countries. An item that is coded once can be bought, stored, and shipped by any partner nation that reads the same catalog.

The 13-Digit Anatomy of an NSN

Every NSN is 13 digits long. It is usually printed in four groups, like this:

5305-01-234-5678

The dashes are just for reading. Underneath, those 13 digits carry three pieces of information.

The first 4 digits: the Federal Supply Class (FSC)

The FSC tells you what family of items you are looking at. It groups similar things together. As an example, FSC 5305 covers screws, and FSC 5310 covers nuts and washers. If you know the FSC, you already know the rough category before you read a single line of the item description.

The first two digits of the FSC are the Federal Supply Group (FSG). The FSG is the broad family; the FSC is the specific class inside it. So FSC 5305 sits inside FSG 53, which is hardware.

The next 2 digits: the country code

These two digits identify the country that cataloged the item — technically its National Codification Bureau code. For the United States, the code is 00, and 01 is also used. When you see a country code that is not the United States, you are looking at an item first cataloged by a partner nation under the shared NATO system.

The last 7 digits: the item number

These seven digits are the "non-significant" number. That means the digits themselves have no meaning — they are simply a serial number that makes this NSN unique. Two items in the same FSC get different seven-digit tails.

Putting it together: the NIIN

Now add the last 9 digits together — the 2-digit country code plus the 7-digit item number. That 9-digit block is the National Item Identification Number, or NIIN. So the full formula is simple:

NSN (13 digits) = FSC (4 digits) + NIIN (9 digits)

In our example, 5305-01-234-5678 is FSC 5305 plus NIIN 012345678. The NIIN is the number that is unique to the item across the whole NATO system. The FSC tells you the category; the NIIN tells you which item.

How to Look Up an NSN Number Step by Step

You have two paths. One is free and open to the public. The other needs a government-issued login. Start with the free one. Most of what a supplier needs is there.

Step 1: Decide what you are starting with

Before you search, be clear about your starting point. You might have an NSN and want the item details. You might have a part number and want the NSN. Or you might have a description and want to find the right NSN. Each path uses the same tool but a different search field.

Step 2: Download PUB LOG for free NSN data

PUB LOG (Public Logistics Data) is DLA's free, publicly releasable catalog data. It requires no subscription and no Common Access Card. DLA publishes it as monthly downloads that you install on your own computer or local network. You can grab the full package from DLA's PUB LOG page at https://www.dla.mil/Information-Operations/Services/Applications/PUB-LOG/ or the individual files from the FLIS Data Electronic Reading Room at https://www.dla.mil/Information-Operations/FLIS-Data-Electronic-Reading-Room/.

Inside PUB LOG you get searchable NSN products. The ones that matter most for a lookup are:

• FLIS Data — every active, non-restricted NSN and its supply data. Search by FSC, NIIN, item name, or characteristics.
• Master Cross Reference Data (MCRD) — NSNs, part numbers, and Commercial and Government Entity (CAGE) code data cross-referenced to each other.
• Management Data Interchangeability and Substitutability (MDI&S) — whether one item can replace another.
• H-Series — the handbooks behind the codes, including H2 for Federal Supply Classification and H6 for item names.

Step 3: Search by the field you actually have

Open the interactive query in PUB LOG and pick the right field:

• Have an NSN? Type the full 13 digits and pull the item name, characteristics, and reference data.
• Have a part number? Search MCRD by part number (labeled PARTNBR) to find the NSN or NSNs it maps to.
• Have a description? Search FLIS Data or Characteristics data by item name or by a physical characteristic, then narrow by FSC.
• Have a manufacturer? Search MCRD by CAGE code to see everything that company is linked to.

If you would rather watch someone do it, DLA publishes a short "What is an NSN?" training video that explains how the number is built: https://www.dla.mil/Customer-Support/Training/Details/Article/3943225/dla-fast-faqs-what-is-an-nsn/.

Step 4: Use WebFLIS when you need live, controlled-access data

WebFLIS (Web Federal Logistics Information System) is DLA's web interface into the Federal Logistics Information System (FLIS). It shows NSNs, item names, and the manufacturers and suppliers behind them, including part numbers. The catch is access. WebFLIS is a controlled system — you need a Common Access Card (CAC), an External Certificate Authority (ECA) certificate, or Federal Bridge authentication. DLA describes it here: https://www.dla.mil/Working-With-DLA/Applications/Details/Article/2876998/webflis-web-federal-logistics-information-system/.

Government-sponsored contractors doing business with the United States can qualify. Accounts are issued through DLA's Account Management and Provisioning System (AMPS). If you are a small business without a certificate yet, stay on PUB LOG until your registration and sponsorship are in place.

Step 5: Cross-check the item on FedMall and DIBBS

Two more DLA systems help you confirm what you found. FedMall is the Department of Defense eCommerce ordering system. Customers and suppliers reach it through the Procurement Integrated Enterprise Environment (PIEE) at https://piee.eb.mil/. DIBBS, the DLA Internet Bid Board System, is where DLA posts the solicitations built on those NSNs. You can reach DIBBS at https://www.dibbs.bsm.dla.mil/. Searching DIBBS by NSN tells you whether the government is actively buying that item right now.

How to Find Out Who Supplies an Item

This is the question behind most NSN lookups. People are not just curious about a part — they want to know who makes it and who sells it. The lookup results answer that if you know which field to read.

Start with the CAGE code. A CAGE code is a Commercial and Government Entity code: a five-character identifier the government assigns to a specific facility, whether that is a manufacturer, a distributor, or a dealer. It is tied to a physical location, not just a company name.

The link between an NSN and a supplier runs through the part number. A single item usually has several part numbers, because several companies make or stock the same item. Each part number carries the CAGE code of the company that owns it. Cross-reference that data and you get a list of who is tied to the item.

That cross-reference is exactly what MCRD is for. Master Cross Reference Data ties NSNs, reference numbers, and CAGE codes together, and it adds the Source of Supply and related data on top. Search MCRD by NSN and you see the part numbers and CAGE codes linked to it. Search by part number and you see every NSN that part is tied to. Search by CAGE and you see everything that supplier is connected to.

A few practical notes when you read supplier data:

• An approved source is not the same as the only source. The government may buy from several qualified suppliers for one NSN.
• A CAGE code is not a quality rating. It only identifies the facility. It says nothing about whether that supplier can currently perform.
• The manufacturer and the seller can be different companies. The maker holds the design; a distributor may hold its own CAGE code and part number for the same item.
• Source of Supply matters. The listed source tells you how DLA manages the item — whether it is bought through DLA, another service, or set aside for small business.

If the item has no NSN yet because it is new or commercial, the picture changes. DLA publishes an NSN Assignment Process Flow Guide that shows how a civilian vendor's item gets cataloged: https://www.dla.mil/Working-With-DLA/Federal-and-International-Cataloging/. That path is worth knowing if you want to sell an item the government does not yet buy by NSN.

NSN vs. NIIN vs. Part Number: What Is the Difference?

Three terms get mixed up constantly. Getting them straight will save you real confusion.

An NSN is the full 13-digit National Stock Number. It is the complete address: category plus item, country included.

A NIIN is the National Item Identification Number — the last 9 digits of the NSN. It is the unique item identifier by itself, without the category prefix. Two NSNs can never share a NIIN, because the NIIN alone is enough to single out the item across the whole NATO system.

A part number is the manufacturer's own label for the item. It is assigned by a company, not by the government, and it is not unique across companies. Ten different firms can each have a part number that reads the same and means ten different things. The part number only becomes reliable once it is tied to a CAGE code, which pins it to one specific company.

Here is the clean way to hold it in your head:

• The government identifies items by NSN (and by NIIN inside it).
• Companies identify items by part number plus CAGE code.
• The bridge between the two is the cross-reference data — the part number, the CAGE code, and the NSN pointing at each other.

You also hear NSNs called "national stock numbers" and "NATO stock numbers." Those are two names for the same thing. The United States and its partners use one shared system, so the number works on both sides of the Atlantic.

Why Suppliers Care About NSN Lookup

If you sell to DLA, the NSN is not trivia. It is how the work arrives.

DLA posts solicitations on DIBBS, and those solicitations are keyed to an NSN. The buyer is not asking you to invent anything. They are saying, in effect: here is the NSN, here is the quantity, here is the delivery date — quote us a price. A Request for Quotation (RFQ) built on an NSN is a known, repeatable demand signal. That is a very different world from cold-selling a product nobody asked for.

That means your first move on any opportunity is an NSN lookup. You want to know what the item actually is, who currently supplies it, how many approved sources exist, and whether the buying is steady. A part with steady demand and few sources is a better target than a part with many suppliers chasing the same orders.

The NSN also tells you how to price and whether you can even source the item. If your manufacturer is already an approved source, you are closer to a winning quote. If not, you may need to cross the manufacturer's part number to the NSN and prove your item meets the specification.

This is also where a lot of new vendors get the fundamentals right but stumble on the rest. Registering to quote and staying compliant are separate jobs from reading an NSN correctly. If you are new, start with a clean setup: see our step-by-step guide on how to register on DIBBS so your quotes are accepted the first time. Then read our breakdown of government contracting compliance requirements so you do not lose an award after you win it.

Finally, price the number, not the wish. A DLA buyer compares your quote against a known item and a known history. Our guide to government contract pricing strategy walks through how to build a bid that wins and still makes money.

Put it together and the NSN becomes a tool, not a mystery. Look up the number. Learn the item. Find the sources. Then decide whether the order is worth your time.

Frequently Asked Questions

What does an NSN number look like?

An NSN is 13 digits, usually written in four groups separated by dashes: for example, 5305-01-234-5678. The first four digits are the Federal Supply Class (FSC), the next two are the country code, and the last seven are the item number. The final nine digits — country code plus item number — make up the National Item Identification Number (NIIN).

Is NSN lookup free?

Yes, the basic lookup is free. DLA publishes PUB LOG, its Public Logistics Data, as free monthly downloads that anyone can install on a computer. No subscription and no Common Access Card are required. WebFLIS and FedMall give you more detail but need a government certificate or a sponsored account, which most small businesses qualify for once they are registered.

What is the difference between an NSN and a NIIN?

The NSN is the complete 13-digit National Stock Number. The NIIN is the National Item Identification Number — the last 9 digits of the same NSN. The NIIN identifies the item by itself, while the NSN adds the 4-digit Federal Supply Class at the front so you also know the item's category.

How do I find out who supplies an item for an NSN?

Use DLA cross-reference data. Search by the NSN in Master Cross Reference Data (MCRD), part of the free PUB LOG download, and you will see the part numbers and Commercial and Government Entity (CAGE) codes linked to the item. Each CAGE code points to a specific facility that makes or stocks the item. WebFLIS shows the same supplier and part-number links if you have access.

Do I need a CAC to run an NSN number lookup?

No. The free PUB LOG download does not require a Common Access Card or any login. You only need a CAC, an External Certificate Authority certificate, or Federal Bridge authentication to reach controlled systems like WebFLIS. For most supplier research, the free public data is enough to start.