“Alphabet Soup” Glossary: UEI, CAGE, NAICS, PSC, CO, COR


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Glossary of government contracting acronyms like UEI, CAGE, and NAICS

Federal contracting runs on acronyms, and the jargon stops more small businesses than the actual work does. This glossary defines the terms that matter — grouped by identity codes, classification codes, and key people — in plain English.

Quick Answer

The core federal contracting acronyms fall into three groups: identity codes (UEI, CAGE, SAM — who your business is), classification codes (NAICS, PSC, FAR — what your business does), and key people (CO, COR, OSDBU — who you'll work with). Master these and the rest of the vocabulary falls into place.

Federal contracting runs on acronyms. In your first week you will encounter UEI, CAGE, NAICS, PSC, CO, COR, FAR, SAM, and a dozen more — often with no explanation. This glossary defines the ones that actually matter for a small business entering the federal market, grouped so you can see how they fit together.

Federal Contracting Acronyms at a Glance Identity Codes WHO YOU ARE UEIUnique Entity Identifier CAGECommercial & Gov Entity SAM · Login.gov · MPIN Classification WHAT YOU DO NAICSIndustry code PSCProduct Service Code FAR · set-aside · size std Key People WHO YOU MEET COContracting Officer CORCO's Representative CS · OSDBU · SBS
The federal contracting acronyms every new vendor needs, grouped by function: identity codes (who you are), classification codes (what you do), and the key people you will encounter.

Identity Codes: Who Your Business Is

These codes establish your business as a recognized federal vendor. You cannot bid on a federal contract without them.

UEI — Unique Entity Identifier

Your business's official federal ID number, assigned through SAM.gov during registration. The UEI replaced the old DUNS number system. Every entity doing business with the federal government needs one, and it is required to bid on or receive a federal contract.

CAGE — Commercial and Government Entity Code

A five-character code that identifies your business location for procurement and payment. For U.S. entities, CAGE is typically assigned automatically as part of SAM.gov registration. (Non-U.S. entities receive an NCAGE code.)

SAM — System for Award Management

The official U.S. government portal where you register your entity, get your UEI, complete your Reps & Certs, and search contract opportunities. Registration is free. See our complete SAM.gov registration guide.

MPIN — Marketing Partner ID Number

A self-created password-like code in your SAM registration that grants access to other government systems and authorizes certain actions. Treat it like a sensitive credential.

Trust note: SAM.gov registration and your UEI are completely free through the official government website. Any email or service demanding payment to register or renew in SAM.gov is a scam.

Classification Codes: What Your Business Does

These codes tell the government what you sell and determine which opportunities and size standards apply to you.

NAICS — North American Industry Classification System

Six-digit codes that classify your industry. Your primary NAICS code should match your core business; you can add secondary codes for related capabilities. NAICS codes drive two critical things: which opportunities match your business, and whether you count as “small” under the SBA size standard for that code.

PSC — Product Service Code

A code agencies use to classify the specific product or service being purchased. Where NAICS describes your industry, PSC describes the exact thing the government is buying. Matching your capabilities to the right PSCs helps you find and filter relevant opportunities.

FAR — Federal Acquisition Regulation

The primary rulebook governing how federal agencies buy goods and services. Every federal contract contains FAR clauses that are legally binding. You do not need to memorize it, but you should understand the parts relevant to your work. See What the FAR Is.

Size Standard — SBA Size Standard

The revenue or employee-count threshold that determines whether your business qualifies as “small” under a given NAICS code. Size is NAICS-specific — you can be small under one code and other-than-small under another.

Key People: Who You'll Encounter

Knowing who does what inside an agency keeps you from knocking on the wrong door.

CO — Contracting Officer

The only person with legal authority to enter into, administer, or terminate a federal contract. The CO runs the procurement and makes the award decision. Do not cold-pitch COs — engage through proper channels first.

COR — Contracting Officer's Representative

The government representative who monitors technical performance after award. The COR manages the day-to-day of the work but does not have authority to change the contract — only the CO can do that.

CS — Contract Specialist

Assists the CO with market research and drafting solicitations. Contract specialists are often involved early, which is why a well-timed capability statement can influence how a solicitation is written.

OSDBU — Office of Small and Disadvantaged Business Utilization

Most agencies have one. The OSDBU promotes small business participation, hosts outreach events, and publishes vendor contact directories. It is often the best first point of contact at a new agency.

SBS — SBA Small Business Search

The database (formerly DSBS) contracting officers use to find small business vendors during market research. A complete, keyword-rich SBS profile makes your business discoverable before you ever submit a proposal.

Acronyms Mapped to the Contracting Journey RegisterUEI · CAGE · SAM ClassifyNAICS · PSC Get foundSBS · OSDBU Find workSources Sought · RFP PerformCO · COR · CPARS Every acronym maps to a stage of the journey — that's all the “alphabet soup” really is
The acronyms are not random — each maps to a stage of the contracting journey: register (UEI/CAGE/SAM), classify (NAICS/PSC), get found (SBS/OSDBU), find work (Sources Sought/RFP), and perform (CO/COR/CPARS).

Opportunity & Process Terms

Sources Sought — Sources Sought Notice

A market research notice agencies post before writing a solicitation. Responding demonstrates your capability and can influence whether a contract becomes a small business set-aside. One of the most underused tools available to small vendors.

RFI / RFQ / RFP — Request for Information / Quote / Proposal

The three main solicitation types. An RFI gathers market information; an RFQ requests a price quote for simpler buys; an RFP requests a full proposal for complex requirements.

Set-Aside — Small Business Set-Aside

A contract reserved exclusively for small businesses, barring large corporations from bidding. See Set-Asides Explained.

Simplified Acquisition — Simplified Acquisition Procedures

Streamlined procedures for contracts under $250,000. Faster timelines and less paperwork — often the best entry point for new federal contractors.

CPARS — Contractor Performance Assessment Reporting System

The government system where your contract performance is rated after completion. CPARS ratings are a permanent record that future evaluators read when scoring your proposals.

Field Note — Former Contracting Officer Perspective

The acronyms intimidate people out of federal contracting more than the actual work does. But every one of these is just a label for something simple. UEI is your ID. NAICS is what you do. The CO makes the decision. Once the vocabulary clicks, the whole system stops feeling like a foreign language — and you start seeing the opportunities that were there all along.

Biz2Gov · Connect. Compete. Succeed.

Ready to Take Your First Step?

Biz2Gov helps small businesses go from unregistered to pipeline-ready in 90 days. Founded by former DoD Contracting Officer Bruce Ayres, we provide hands-on implementation — not just advice.

Frequently Asked Questions

A UEI (Unique Entity Identifier) is your business's primary federal ID number, assigned through SAM.gov and required to bid on contracts. A CAGE (Commercial and Government Entity) code is a five-character code identifying your business location for procurement and payment, typically assigned automatically during SAM registration.
NAICS codes classify your industry (what kind of business you are) and determine your size standard. PSC codes classify the specific product or service the government is buying. NAICS describes you; PSC describes what's being purchased.
A Contracting Officer (CO) has legal authority to award, modify, and terminate contracts. A Contracting Officer's Representative (COR) monitors technical performance after award but cannot change the contract. Only the CO can modify contract terms.
No. Focus first on the identity codes (UEI, CAGE, SAM), your classification codes (NAICS, PSC), and the key people (CO, OSDBU, Small Business Specialist). You'll pick up the rest as you go. The vocabulary is just labels for straightforward concepts.
CPARS (Contractor Performance Assessment Reporting System) is where the government records your performance rating after a contract is completed. It's a permanent record that future contracting officers read when evaluating your proposals, so strong CPARS ratings are a valuable long-term asset.

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