220+ of the acronyms you'll meet in federal contracting — in plain English, with why each one matters.
Published June 5, 2026 · Updated September 28, 2026 by the Government.biz editorial team.
Federal contracting runs on acronyms. A single solicitation can throw a dozen of them at you in the first paragraph — and guessing wrong can cost you a bid. This glossary collects the terms that come up most often when you register, certify, propose, price, perform, and get paid, grouped by where you'll run into them. Where we have a full guide, the term links to it.
Two cautions. First, some acronyms mean different things in different places (CR, SSP, and BAA each have two common meanings) — we flag those. Second, agencies coin local abbreviations; if a term isn't here, check the acronym list at the end of the solicitation, which controls for that contract. Dollar thresholds are as of September 2026.
Lost a competition? A debriefing is where you learn why — see debriefings.
More on defense work: defense contracting.
Presenting yourself to primes and agencies? Start with a strong capability statement.
These come up in searches but don't have a single governmentwide meaning. Here is what we could verify — always defer to the acronym list in your solicitation.
CLIN stands for Contract Line Item Number — a numbered line (0001, 0002, and so on) in Section B of a contract that identifies a separately priced deliverable or service, with its own quantity, unit, price, and often its own funding and contract type. Sub-lines are SLINs (for example 0001AA), and ACRNs tie each line to the accounting data that funds it. You invoice against CLINs, so how they are structured drives how you get paid.
The Contracting Officer (CO, also written KO) is the only official with a warrant — the legal authority to sign, change, or terminate a contract on the government's behalf. The Contracting Officer's Representative (COR, formerly COTR) is a technical monitor the CO designates in writing to oversee day-to-day performance, inspect work, and review invoices. A COR cannot change price, scope, or schedule; if a COR directs extra work, get the change from the CO in writing before you perform it.
FFP means Firm-Fixed-Price — a contract type where the government pays a set price for the defined work regardless of what it actually costs you to perform. You keep the savings if you come in under cost and absorb the loss if you overrun, so FFP puts the most cost risk on the contractor. It is the most common contract type and the default for commercial products and services.
The Revolutionary FAR Overhaul (RFO) is the rewrite of the Federal Acquisition Regulation launched under Executive Order 14275 in April 2025 to strip the FAR back to statutory requirements and plain language. In 2025 the FAR Council released model deviation text part by part, which agencies adopted through class deviations. Formal rulemaking began with proposed rules published June 23, 2026 and a second set on September 18, 2026 (comments due October 19, 2026). As of September 28, 2026 no final rule has been issued, so check each solicitation for which FAR text and deviations apply.
An IDIQ (Indefinite Delivery/Indefinite Quantity) is a contract type: an umbrella contract with a minimum and maximum under which the government issues task or delivery orders. A GWAC (Governmentwide Acquisition Contract) is a multi-agency IDIQ for IT that any agency can order from, such as Alliant 3, 8(a) STARS III, or NASA SEWP. The GSA Schedule (Multiple Award Schedule, MAS) is a separate long-term governmentwide program with pre-negotiated pricing, organized by Special Item Numbers (SINs), that agencies order from directly or through BPAs.
FOF has no definition in the FAR. In government contract documents it most often means Force-on-Force — the performance-testing exercises in protective-force and security contracts, such as Department of Energy and NNSA security services contracts, where an adversary team tests the guard force. If you see FOF somewhere else, check the solicitation's own acronym list, because agencies define local abbreviations.
New to all of this? Start with the SAM.gov registration guide and NAICS codes, then read our 90-day roadmap to your first government contract. Browse the full resource hub for guides on certifications, compliance, proposals, and contract management, or grab the checklists and templates.