Winning a set-aside contract comes with a string attached that catches a lot of new primes off guard. You can't take the award and quietly pass most of the work to a large business while you collect a margin in the middle. The government set those contracts aside for small firms so small firms would do the work. The rule that enforces that is the limitation on subcontracting, and most people in GovCon call it the 50% rule.
It lives in FAR 52.219-14 and 13 CFR 125.6, and it applies to most set-aside and sole-source awards above the simplified acquisition threshold: small business set-asides, 8(a), HUBZone, WOSB and EDWOSB, and SDVOSB. If you're chasing set-aside work, this is the compliance line you cannot cross.
What the rule actually saysThe rule limits how much of the contract you're allowed to pay out to subcontractors. Not how much work you subcontract in some abstract sense, but the dollars. It's measured against the amount the government pays you.
Here are the percentages, by contract type, current under FAR 52.219-14:
- Services: the prime must not pay more than 50% of the amount the government pays it to subcontractors that are not similarly situated.
- Supplies (other than from a regular dealer): same 50% cap, excluding the cost of materials.
- General construction: the prime must not pay more than 85% to non-similarly-situated subs, excluding materials.
- Special-trade construction: the prime must not pay more than 75%, excluding materials.
Read those carefully, because the framing matters. The rule isn't "you must perform 50% of the work." It's a cap on what you pay out to the wrong kind of subcontractor. On a services contract, you can subcontract as much as you want to the right kind of firm. What you can't do is route more than half the government's payment to firms that don't count toward your share.
That distinction is the whole game, and it turns on one term.
Similarly situated entity: the term that changes the mathA similarly situated entity is a subcontractor that holds the same small-business or set-aside status as the prime and is small under the NAICS code the prime assigned to the subcontract. On an 8(a) set-aside, a similarly situated sub is another 8(a) firm that's small under that NAICS. On a WOSB set-aside, it's another WOSB. On a small business set-aside, it's any small business under the assigned size standard.
Here's why it matters. Work performed by a similarly situated subcontractor does not count against your 50%. The statute treats your payments to those firms as if you performed the work yourself. So a single small prime can team with several similarly situated subs, split the work among them, and stay compliant, because none of those dollars land in the non-similarly-situated bucket.
A quick example. You win a $1,000,000 services set-aside. You can pay up to $500,000 to subs that are not similarly situated. If you pay $400,000 to a large subcontractor, you're fine. Add a $300,000 similarly situated small-business sub on top, and you're still fine, because that $300,000 doesn't count toward the cap. The only number the rule watches is the money going to firms outside your set-aside category.
This is the structure that makes small-business teaming work. It's also why getting your partners' status right before award matters more than almost anything else in the deal.
Why the rule existsThe set-aside programs exist to channel federal spending to small and diverse businesses. Without a limitation on subcontracting, the easiest way to game that would be a pass-through: a small firm wins the set-aside, subcontracts 90% of the work to a large incumbent, and acts as a billing front. The small business gets a cut, the large business does the work, and the program delivers nothing it was built to deliver.
The 50% rule closes that door. It forces the firm that holds the set-aside status to either perform the bulk of the work itself or share it with other firms that qualify. Contracting officers know the pattern, and the consequences for a sham arrangement are serious.
How compliance is measuredTwo things to get straight. First, the cap is measured over the period of performance, not invoice by invoice. You can be heavier on subcontractors early and pull the ratio back later; what matters is where you land across the life of the contract. For multiple-award and IDIQ-type vehicles, compliance is generally assessed at the order level unless the contracting officer sets it at the contract level.
Second, the burden is on you to prove it. Contracting officers can require you to represent your compliance, and on some procurements you'll certify it. The SBA can request documentation. If a competitor protests that you can't meet the limitation, you may have to show your subcontracting plan and your teaming arrangements to defend the award. Keep clean records of what you paid, to whom, and each subcontractor's size and status as of the date of the subcontract.
A practical move: lock down each sub's similarly-situated status in writing before you sign anything. A sub that was small last year but blew past the size standard can quietly turn into a compliance problem you didn't see coming.
Penalties for getting it wrongThis isn't a soft rule. Violating the limitation on subcontracting can carry real consequences:
- Loss of the award or termination. A pre-award protest can cost you the contract. A post-award finding can lead to termination.
- False Claims Act exposure. If you certified compliance and didn't meet it, the government can treat that as a false claim, which opens the door to treble damages and per-claim penalties. This is where casual pass-throughs become very expensive.
- Suspension and debarment. A serious or repeated violation can get a firm barred from federal contracting.
- Reputational damage with the contracting officer who relied on your representation, which follows you into your past-performance record.
The recurring theme in enforcement cases is the pass-through: a small prime that exists mostly to invoice while a large business runs the job. Don't build a deal that looks like that, even if your intentions are clean.
How it interacts with joint ventures and teamingThis is where small firms get tripped up, because the rule applies differently depending on how you partner.
In a joint venture, the limitation is applied to the JV as a whole, and a special split governs the work between the partners. The work the JV performs (not subcontracts out) must be split so the small-business partner does a meaningful share, and the JV measures its subcontracting against the relevant percentage. JVs let a smaller firm pair with a larger mentor and still hold a set-aside, but only if the structure follows SBA's rules. The details are strict, and they've been changing.
In a prime-subcontractor teaming arrangement, you're the prime and you carry the limitation yourself. Your teammates' status determines whether their work counts toward your cap. Similarly situated teammates help you; large teammates eat into your 50%. Choosing between these two structures is a real decision with different liability and compliance math, which we break down in teaming agreement vs joint venture.
Either way, the planning happens before the bid, not after the award. By the time you're invoicing, the ratio is mostly set.
Build your team around the rule, not against itThe limitation on subcontracting isn't a trap to fear; it's a constraint to plan around. The firms that win and keep set-aside work treat it as a teaming strategy: line up similarly situated partners so the dollars stay inside your category, perform a real share yourself, and document status before anyone signs.
If you're sizing up where you fit on a contract, as a prime who needs qualified small-business subs or as a sub looking to get onto a prime's team, start with our subcontract finder. It helps you find the partners and opportunities that keep you on the right side of the 50% line. And if you're still earlier in the process, how to find federal contract opportunities covers where the work shows up in the first place.
