Small Business Set-Asides Under FAR Part 19.5

A “small business set-aside” is a federal acquisition restricted, in whole or in part, to small business concerns under Federal Acquisition Regulation (FAR) Subpart 19.5. For a research institution that both holds federal contracts and buys goods and services with federal funds, that definition matters in two directions at once: as a buyer, your procurement office has to know when a purchase must or may be set aside and how to confirm a vendor actually qualifies; as a prime contractor on larger federal awards, your own subcontracting plan is scored against how much of that spend flows to small businesses in specific socioeconomic categories. This guide covers both, from the procurement/contracts-office side — not as a how-to for a small business trying to win a set-aside contract.

The FAR Part 19.5 set-aside categories

FAR Subpart 19.5 defines three kinds of set-aside:

• Total set-aside — the entire requirement is restricted to small business competition.
• Partial set-aside — the requirement is split into a small business portion and an unrestricted portion, used when a total set-aside isn’t feasible but part of the work can still be reserved.
• Class set-aside — a set-aside determination applied to a whole category of future acquisitions for a given product or service line, rather than decided contract-by-contract.

Every set-aside solicitation must specify the applicable NAICS code and the SBA size standard tied to it (FAR 19.5) — the size standard, not a flat revenue or headcount number, is what actually determines whether a given vendor counts as “small” for that procurement.

The Rule of Two, and where it sits relative to acquisition thresholds

FAR 19.502-2 is the “Rule of Two”: a contracting officer must set aside an acquisition for small business if there’s a reasonable expectation that offers will be received from at least two responsible small business concerns, at fair market prices. How that obligation applies changes by dollar tier:

• Below the micro-purchase threshold — set-asides aren’t required.
• Micro-purchase threshold to the simplified acquisition threshold (SAT) — the contracting officer shall set the acquisition aside for small business unless two or more small businesses reasonably capable of competitive pricing can’t be found.
• Above the SAT — a set-aside becomes discretionary rather than automatic, but is still required when the Rule of Two’s reasonable-expectation test is met.

The current federal micro-purchase threshold is $15,000 and the current simplified acquisition threshold is $350,000, both effective October 1, 2025 under the FAR’s statutory inflation adjustment (up from $10,000 and $250,000) — see CASRAI’s Simplified Acquisition Threshold and Micro-Purchase Threshold guide for the full current threshold table and how it interacts with 2 CFR 200 for non-federal recipients. That guide is the place to check the numbers; this one is about what the numbers trigger under Part 19.5.

Set-aside programs a vendor can qualify under

“Small business set-aside” is the umbrella; a specific vendor may also carry one of several socioeconomic certifications layered on top of plain small-business status, each with its own eligibility program administered by the Small Business Administration (SBA):

• 8(a) Business Development Program — socially and economically disadvantaged small businesses; SBA-certified, time-limited (generally a nine-year program term), and eligible for both competitive and, below certain thresholds, sole-source 8(a) awards.
• HUBZone — small businesses located in and employing residents of Historically Underutilized Business Zones.
• Women-Owned Small Business (WOSB) / Economically Disadvantaged WOSB (EDWOSB) — set-asides in industries where SBA has identified women-owned businesses as underrepresented or substantially underrepresented.
• Service-Disabled Veteran-Owned Small Business (SDVOSB) and Veteran-Owned Small Business (VOSB) — the VA’s Vets First program runs a parallel track for VA procurements specifically.

A vendor can be a plain small business set-aside participant without holding any of these certifications — the certifications layer additional, narrower set-aside eligibility on top of general small-business status; they don’t replace it.

Verifying a vendor’s set-aside eligibility before you award

Before a procurement office can rely on a vendor’s small-business or socioeconomic-category claim, FAR 19.5 and SBA regulations give it two practical verification paths:

• SAM.gov representations and certifications — an active System for Award Management registration includes the vendor’s self-certified size and socioeconomic representations for the applicable NAICS code(s). A procurement office can rely on a current SAM.gov certification as long as the vendor represents those entries are current, accurate, and complete as of the date of its offer.
• Written representation with the offer — the same rule applies if the vendor instead certifies its size/status directly in its proposal or quote, current as of that date.

If a vendor’s small-business status is later challenged — by a competitor or by your own contracting office — size protests are resolved by SBA’s Office of Government Contracting under 13 CFR 121.1001–121.1008, not decided unilaterally by the procurement office itself. A contracting officer who has reason to question a vendor’s size representation refers the question to SBA rather than simply rejecting the offer.

What counts toward your institution’s own subcontracting-plan goals

This is the side of Part 19.5 that’s easy to miss from the buying side alone: if your institution itself holds a federal contract (as distinct from a grant or cooperative agreement — see CASRAI’s guide on when a federal award is a contract rather than a grant) that exceeds $900,000 ($2 million for construction) and has subcontracting opportunities, FAR Subpart 19.7 requires your institution to submit and perform against an individual subcontracting plan under FAR 52.219-9. Small businesses themselves, personal-services contracts, and work performed entirely outside the U.S. are exempt from this requirement.

The plan sets separate percentage goals for subcontracting dollars flowing to:

• Small businesses generally (including Alaska Native Corporations and Indian tribes)
• Small disadvantaged businesses (SDB)
• Women-owned small businesses (WOSB)
• HUBZone small businesses
• Veteran-owned small businesses (VOSB)
• Service-disabled veteran-owned small businesses (SDVOSB)

A subcontract only counts toward these goals if the subcontractor genuinely qualifies in that category at the time of award — which is exactly why the verification step above (a current SAM.gov certification or written representation) isn’t a formality. Performance against the plan is reported through the Electronic Subcontracting Reporting System (eSRS), and a pattern of relying on unverified vendor self-representation is a real audit exposure, not just a paperwork gap. This is the same discipline that governs downstream subrecipient risk more broadly — see CASRAI’s Subrecipient Monitoring Checklist for the parallel obligations that apply once a subaward, rather than a commercial subcontract, is involved.

Frequently asked questions

What is a small business set-aside?

It’s a federal acquisition, or a defined portion of one, that a contracting officer restricts to small business competition under FAR Subpart 19.5, based on the Rule of Two’s reasonable expectation that at least two responsible small businesses will submit competitively priced offers.

What are the small business set-aside requirements?

The solicitation must specify the NAICS code and SBA size standard that defines “small” for that procurement, and the set-aside decision itself follows the Rule of Two: mandatory between the micro-purchase threshold and the simplified acquisition threshold absent a documented inability to find two qualified small businesses, and discretionary (but still expected where the Rule of Two is met) above the SAT.

What are small business set-aside contracts?

They’re the contracts actually awarded under a set-aside decision — total, partial, or class — as opposed to a contract awarded through full and open competition where small-business status wasn’t a factor in who could compete.

Does a small business set-aside purchase automatically count toward our subcontracting plan?

Only if your institution is itself a prime contractor with a FAR 52.219-9 individual subcontracting plan in force, and only if the vendor’s small-business/socioeconomic status is current and verifiable (SAM.gov or a written representation) at the time of that subcontract’s award — an expired or unverifiable certification doesn’t count, even if the purchase itself was correctly set aside.

How does a procurement office verify a vendor’s set-aside eligibility?

By checking the vendor’s current System for Award Management (SAM.gov) size and socioeconomic representations for the applicable NAICS code, or accepting an equivalent current written representation with the vendor’s offer — and referring any genuine dispute to SBA’s size-protest process under 13 CFR 121.1001–121.1008 rather than resolving it internally.