TriNet vs Justworks: 2 Small Business PEOs Compared

I have sat through this comparison twice with founders, and both times it ended somewhere the spreadsheet did not predict. One company had 14 people and picked the provider with the higher administrative fee, because the health plan quote came back $900 a month cheaper. The other had 60 people and went the opposite way for the same reason. The admin line moved by a few hundred dollars. The premium line moved by thousands.

That is the first thing to understand about TriNet versus Justworks. These are not software subscriptions you can rank on features. They are professional employer organizations, which means they become a co-employer of your staff, file payroll taxes under their own tax ID, and sell you access to their group insurance. The advertised rate is the smallest number on the invoice.

Where the two genuinely differ is structural, and one difference is visible before you talk to anyone: Justworks publishes its rates and TriNet does not. That single fact shapes how each company sells, who each one takes on, and how much homework you have to do before you can compare them at all.

TriNet vs Justworks at a glance

Both are certified professional employer organizations that run payroll, file employment taxes under their own tax ID, administer benefits, and provide workers compensation coverage. The differences sit in pricing transparency, minimum size, how benefits administration is packaged, and how much of the service is shaped around your industry.

Read that table as two different sales models rather than two different feature sets. Justworks is built to be bought without a conversation, which is why every rate sits on a public page. TriNet is built around a consultative quote, which gives it room to price a 12-person consultancy and a 400-person manufacturer differently, and gives you no way to compare until you have talked to someone.

Justworks reviewed

Justworks is the most transparent provider in a category that hides everything. Its pricing page lists a rate for every tier and every add-on, states there is no implementation fee, and lets you start an enrollment account without a demo. In a market where most competitors will not name a number until a sales call, that alone changes how a founder can plan.

The product splits into two PEO plans. Basic at $79 covers payroll and employer tax filings across all 50 states, workers compensation access, employment practices liability insurance, 401(k), compliance alerts, onboarding and offboarding, a document center, and 24/7 support by phone, email, and chat. Plus at $124 adds the part most buyers actually came for: medical, dental, and vision administration through Aetna, UnitedHealthcare, and Kaiser Permanente, plus HSA and FSA accounts, COBRA administration, mental health services, and fertility care.

Enrollment is unusually accessible at the bottom of the market. Justworks requires only two individuals to run payroll, one of whom can be an unpaid owner, and it states on its own help center that it is the only PEO that lets companies with fewer than five employees enroll for health insurance access. Health coverage carries a stricter floor: two benefits-eligible employees who do not share a household or claim each other as dependents, where a benefits-eligible person is a W-2 employee working at least 30 hours a week or a business owner.

The limits are real. Workers compensation runs through the Justworks master policy with limited exceptions, and the company states plainly that it cannot support all businesses, naming high-risk manual labor such as construction as an example of work its carrier declines. Employers in Ohio, Wyoming, Washington, and North Dakota must still buy coverage from the state fund. Payroll cycles are also fixed rather than freely configurable: exempt salaried staff default to semimonthly and non-exempt staff run biweekly.

TriNet reviewed

TriNet is the larger and older of the two. Founded in 1988 and publicly traded, it states that it processed $70 billion in payroll in 2025, and that it works with businesses from five employees to more than 1,000. That range is the point: a company that joins at 20 people does not have to replatform at 300.

The differentiator TriNet leans on is industry specialization. It runs tailored offerings for eleven named verticals including technology, financial services, life sciences, consulting, manufacturing, nonprofits, education, e-commerce, retail, marketing, and media, with service teams that know the compliance and benefits patterns of each. For a business in one of those sectors, that shaping is worth more than a lower headline rate.

Pricing is where TriNet asks for patience. Its pricing page explains the model clearly and makes a genuine argument for it: the fee is flat per worksite employee rather than a percentage of payroll, so administrative charges do not rise when you give someone a raise, and they fall when an employee maxes out Social Security or unemployment tax thresholds. The page also confirms TriNet does not publish standard list pricing and requires a minimum worksite employee count without stating the number. The only figure it shows is an illustration: 20 employees at a $150 rate producing a $3,000 monthly administrative fee, explicitly labelled as an example.

One structural detail deserves attention before signing. Under TriNet PEO, federal payroll taxes and most state and local income taxes are reported under TriNet tax IDs, and W-2s are issued in the TriNet name. California and Oregon income tax withholding, state disability in California and Rhode Island, and paid family leave in Massachusetts and Washington stay under your own tax ID. If you have staff in those states, ask exactly which registrations remain your responsibility.

What each costs at 10, 25, and 50 employees

Only half of this table can be filled in honestly, and that is the finding. Justworks publishes enough to calculate an exact administrative fee at any headcount. TriNet publishes nothing, so every cell in its rows reads Quote.

The pattern inside the Justworks rows is worth reading carefully. Moving from Basic to Plus costs $45 per employee per month, which is $450 more at 10 people and $2,250 more at 50. That is the price of buying group health administration through the PEO rather than sourcing it yourself, and it is the number to weigh against a broker quote on the open market.

Add-ons are the other place the bill grows. Justworks publishes them, which makes the arithmetic possible in advance.

A 25-person team on PEO Plus with time tracking pays $3,300 a month in administrative fees before a single insurance premium. Add dedicated HR consulting and it is $4,050. None of that includes the medical plan, the workers compensation premium, or employer payroll taxes, which is the same caveat TriNet states on its own pricing page. Neither company includes the benefits in the fee that administers them.

What the base tier actually includes

The most common error in this comparison is lining up the $79 Justworks tier against TriNet PEO. They are not equivalent products. TriNet sells one PEO with benefits administration inside the fee, while Justworks separates benefits into the higher tier, so the like-for-like comparison against TriNet is PEO Plus at $124.

Two rows there decide most shortlists. If you need group health administration and you are comparing on price, use $124 rather than $79, and the gap against a TriNet quote narrows considerably. If you are below five people, the comparison mostly ends before it starts, because only one of the two markets to companies that small.

Both companies do clear the compliance bar that matters most. Each appears on the IRS list of certified professional employer organizations, Justworks since January 2017 and a TriNet subsidiary since July 2018. Under the IRS certification program, a CPEO carries sole liability for federal employment taxes on wages it processes, which is a meaningful protection you do not get from an uncertified provider.

Where each is genuinely stronger

Neither provider wins outright. Each has a set of situations where it is clearly the better answer, and the honest version of this comparison is a routing table rather than a verdict.

That last row is not a hedge. Justworks states that its master workers compensation policy has risk limits and cannot cover every business, naming construction-type manual labor and contractor-heavy companies as examples of declines. TriNet does not publish its appetite. Either way, the underwriting decision comes before the software decision, and it is worth putting on the table in the first call rather than the fourth.

How to choose between them

Five questions separate the two faster than any feature list. Work through them in order, because the first two eliminate one provider outright for a meaningful share of readers.

One practical note on health coverage. Small employers who go the standalone route can compare group options through the federal small business health options program, and the Small Business Administration publishes a plain-language guide to the employer obligations a PEO would otherwise absorb. Reading both makes the PEO quote easier to judge, because you can see what you are buying out of.

Before you choose

FirstHR is not a PEO. We do not process payroll, file payroll taxes, administer benefits, or take on co-employment. Both providers above do things we do not, and if payroll and group health are the problem in front of you, one of them is the answer, not us.

The question worth settling before you compare their quotes is whether you want a PEO at all. Co-employment is a structural change rather than a purchase, and it comes with real trade-offs on control, portability, and lock-in that are worth reading about honestly. The alternative is a standalone stack: a payroll provider, an insurance broker, and an HR system you own.

Where FirstHR fits is the layer underneath either decision: onboarding workflows, e-signatures on offer letters and new hire paperwork, employee records and a team directory, document management, and training, at a flat $98 to $198 per month rather than a per-employee rate. If you go with a PEO, that stays your system of record for the paperwork the PEO never touches. If you build a standalone stack instead, it is the HR half of it.

Frequently Asked Questions

Is TriNet or Justworks cheaper?

Nobody can answer honestly without a TriNet quote, because TriNet publishes no standard list pricing. Justworks does: $79 per employee per month on PEO Basic and $124 on PEO Plus, so 25 people cost $1,975 or $3,100 a month in administrative fees. TriNet uses the same flat model and illustrates it with a 20 employee example at a $150 rate, labelled illustrative rather than a rate card. The insurance premiums, quoted separately by both, usually decide the total.

Does Justworks publish its PEO pricing?

Yes, and it is the clearest structural difference between the two. The Justworks pricing page lists Payroll at $8 per employee plus a $50 base fee, PEO Basic at $79, and PEO Plus at $124, with published add-on rates and a statement that there is no implementation fee. TriNet explains its per employee per month model, confirms it is a flat fee rather than a percentage of payroll, and then routes you into a quote request.

What is the minimum number of employees for TriNet and Justworks?

Justworks requires two individuals to run payroll and allows one to be an unpaid owner. TriNet states it works with businesses from five employees to more than 1,000 and confirms a minimum worksite employee count without naming it. Health coverage at Justworks needs two benefits-eligible employees who do not share a household or claim each other as dependents, so a married founding couple alone cannot carry a medical plan.

Does Justworks PEO Basic include health insurance?

No. Basic at $79 covers payroll, employer tax filings, workers compensation access, employment practices liability insurance, 401(k), compliance alerts, and 24/7 support. Medical, dental, and vision administration sit in PEO Plus at $124. TriNet does not split its offering that way, so the like-for-like comparison against a TriNet quote is PEO Plus. Basic customers can offer outside health insurance, but enrollment then lives outside the platform.

Are TriNet and Justworks both certified PEOs?

Yes. Both appear on the IRS list of certified professional employer organizations, Justworks since January 2017 and a TriNet subsidiary since July 2018. The CPEO credential means the provider carries sole statutory liability for federal employment taxes on wages processed on its platform rather than sharing that liability with you. TriNet also states it has been accredited by the Employer Services Assurance Corporation since 1995, a credential Justworks does not publish on its own site.

What is not included in the per employee per month fee?

The benefits themselves. The fee buys administration: payroll processing, tax filing, benefits administration, workers compensation administration, platform access, and HR support. Health premiums are quoted after underwriting, workers compensation premiums after a risk review, and employer payroll taxes such as FICA and state unemployment remain your cost regardless.

Which one is better for hourly or high-risk workers?

Neither is a safe assumption, because workers compensation underwriting decides it. Justworks requires customers on its master policy with limited exceptions and states it cannot support all businesses, naming high-risk manual labor such as construction. Employers in Ohio, Wyoming, Washington, and North Dakota buy from the state fund regardless. TriNet does not publish its appetite but lists manufacturing, retail, and education among the industries it serves.

How hard is it to leave a PEO once you join?

Harder than cancelling software, because you unwind an employment structure. Payroll taxes are reported under the PEO tax ID, so leaving means re-establishing state withholding and unemployment accounts, moving to a direct workers compensation policy, and replacing group health written on the PEO master plan. TriNet notes that most PEOs require an annual agreement and may include early-termination fees, and neither company publishes its contract term, so read the co-employment agreement before signing.