CAGE Code vs. UEI vs. DUNS: What Each One Actually Is

A CAGE code, a UEI, and a DUNS number all get called "your government ID number" in casual conversation, and that habit is exactly what causes the confusion. They are three separate identifiers, built by three separate organizations, for three separate purposes. Only two of them are still in active use. The short version: a CAGE code identifies a physical facility for defense logistics, a UEI identifies a legal entity for federal awards, and a DUNS number used to do part of the UEI's job before the government retired it.

CAGE, UEI, and DUNS at a glance

Every supplier question about these three comes down to one of: which one is current, who issues it, and what it actually points to. Here is the comparison in one place.

The practical takeaway: a current federal supplier needs a CAGE code and a UEI. Nobody needs a DUNS number to register in SAM.gov or to receive a federal award anymore.

What a CAGE code identifies

A CAGE code identifies a specific physical location doing business with the government, not the company as a legal whole. It is a five-character code, letters and digits, issued by the Defense Logistics Agency (DLA), and it predates both of the other two identifiers by decades — CAGE codes were already in use in defense logistics before SAM.gov or Dun & Bradstreet had any role in federal contracting.

Because a CAGE code points to a location rather than a company, a single business with several plants, warehouses, or offices can end up holding a separate CAGE code for each one. That is normal, and it is the reason CAGE codes stay tied so closely to defense supply chains: DLA's logistics systems need to know which specific site shipped or stored a given part, which a company-level identifier cannot tell them. A foreign supplier gets the equivalent identifier, an NCAGE code, through its national codification bureau or NATO's support agency rather than through DLA directly.

What a UEI identifies

A UEI (Unique Entity Identifier) identifies the legal entity itself, and it is generated directly inside SAM.gov rather than by an outside vendor. It is a 12-character alphanumeric value, and its format follows a deliberate set of rules published by the General Services Administration: the letters O and I are never used, so they cannot be mistaken for the digits 0 and 1; the first character is never a zero, since a leading zero can silently get dropped when data is imported into a spreadsheet; the first five characters are structured so they cannot collide with CAGE code formatting; and the final character is a checksum calculated from the eleven before it, so a mistyped UEI is detectable rather than silently wrong.

Unlike a CAGE code, a UEI is not tied to a single site. One legal entity gets one UEI, and that same UEI covers every facility, contract, and award that entity is party to. A UEI is public information: it can be looked up by legal business name inside SAM.gov's entity search without an account, the same way a CAGE code lookup works.

What happened to the DUNS number

The DUNS number was retired as a requirement for federal contracting on April 4, 2022, when SAM.gov's Unique Entity Identifier became the official identifier for doing business with the federal government instead. A DUNS number is nine digits, and it was issued by Dun & Bradstreet, a private business-data company, not a government agency. Before 2022, SAM.gov used the DUNS number as the entity identifier behind the scenes, which is why older contracting guidance still refers to it.

Entities that had an active SAM.gov registration before the cutover had a UEI generated for them automatically inside SAM.gov — nothing needed to be requested or reissued. Since then, the DUNS number has simply had no role in federal registration, award, or reporting systems: it was not merged into the UEI, replaced by an equivalent Dun & Bradstreet number, or kept as a secondary reference field inside SAM.gov. If a business still maintains a DUNS number for reasons unrelated to government work, such as commercial credit reporting, that number continues to belong to that separate, private system — it plays no part in a SAM.gov registration or a federal award.

Do you need a CAGE code and a UEI?

Yes, if the business is a current or prospective federal contractor: the UEI identifies the legal entity for the award, and the CAGE code identifies the specific location fulfilling it. Both are assigned automatically, at no cost, during SAM.gov registration for a US-based entity — there is no separate application or fee for either one once the registration itself is complete.

Not every organization in SAM.gov needs a CAGE code, though. Grant-only registrants and some non-procurement entities can have an active SAM.gov registration and a UEI without ever being assigned a CAGE code, because nothing in a grants-only relationship touches DLA's logistics systems. A supplier bidding on a defense contract, by contrast, will be asked for both identifiers, and a missing or mismatched CAGE code is a common reason a bid package gets flagged for correction. Anyone unsure whether a given supplier's CAGE code is active can run a free CAGE code lookup against the current SAM.gov entity registration extract, which also flags federal exclusions the identifier alone would never reveal.

Why one company can hold many CAGE codes

Because a CAGE code identifies a location and a UEI identifies the legal entity that owns it, the two do not have a one-to-one relationship, and the current SAM.gov data shows that clearly. Across the SAM.gov entity registration extract this site's lookup tool is built on, 6,946 unique entity identifiers appear on more than one registration, and the single most-registered identifier appears on 82 separate registrations — 82 distinct CAGE-coded locations under one legal entity. A national manufacturer with plants in five states is not an edge case; it is exactly what the identifier design expects.

This is also why 794,847 of the 895,429 registrations in that same extract carry a CAGE code while the remaining 100,582 do not: a registration without a CAGE code is not an error, it typically means the entity has never needed one, most often because it registered for grants rather than for DLA-linked procurement. A UEI count and a CAGE code count were never going to match, and treating a mismatch between the two as a data problem is a mistake in itself.

Common mistakes with these identifiers

The most common mistake is treating a UEI and a CAGE code as interchangeable on a form, submitting one where the other is asked for. They come from different systems, have different lengths, and a reviewer checking a submission will not accept one in place of the other. A close second is assuming a DUNS number is still needed somewhere in the SAM.gov registration flow; it is not requested anywhere in current registration, and providing one where a UEI is expected will not satisfy the field.

A third, quieter mistake is assuming a single CAGE code covers an entire company's footprint. If a business operates from more than one address that does work with the government, each address that needs its own CAGE code has to be registered for one — the UEI at the top does not automatically extend to cover new locations. Finally, foreign suppliers sometimes look for a CAGE code where an NCAGE code is what they actually need; the two serve the same purpose but come from different issuing systems, and a US-issued CAGE code is not what a foreign codification bureau assigns.