PEO vs Alternatives: Which HR Model Wins for Your Company

Six HR service models exist for US-based companies. Each was designed for different situations:

• PEO (Professional Employer Organization) — Co-employment model. The PEO is the legal employer for tax, benefits, and workers' comp; you control hiring and operations. US-only. $80–$220+ PEPM.
• EOR (Employer of Record) — Sole employment model in a country/state where you don't have a legal entity. Used for international hiring and US states where you have no presence. Typically 10–20% of gross salary as a fee.
• ASO (Administrative Services Organization) — Like a PEO without the co-employment. You keep your own EIN, benefits, workers' comp; the ASO handles HR/payroll admin. $30–$80 PEPM.
• HR Software Stack — HRIS (BambooHR, Rippling, Gusto solo) + benefits broker + payroll provider + separate workers' comp. You assemble the pieces. $40–$80 PEPM equivalent + your time.
• Payroll-Only Provider — ADP RUN, Paychex Flex, Gusto solo, QuickBooks Payroll. Files taxes, runs direct deposit, prepares W-2s. Doesn't provide group benefits, workers' comp, or HR compliance support. $40–$60 base + $4–$15 per employee monthly.
• In-House HR Team — Your own people. HR director + generalist + payroll specialist + benefits coordinator. $420K–$540K loaded for a 4-person function, supporting 250–500 employees.

The right model depends on four variables: headcount, geographic footprint, benefits priorities, and growth stage. The rest of this guide covers each comparison in depth.

The cleanest mental model: PEO is US-only co-employment; EOR is country-by-country sole employment. They're not really competitors — they solve different problems.

When EOR wins. You're hiring in a country where you don't have a legal entity. France, Germany, India, Brazil, Mexico — establishing a legal entity to hire 2 engineers costs $50K–$200K in setup plus ongoing accounting and compliance overhead. An EOR (Deel, Remote, Velocity Global, Globalization Partners) employs the worker in-country under their entity, handles local tax and benefits compliance, and bills you a fee. Same logic applies for some US states — if you're a California company and need to hire one person in Wyoming or New Jersey without registering as an employer in that state, an EOR can bridge the gap.

When PEO wins. You're hiring US-based employees and want the bundle (benefits, payroll, workers' comp, compliance) under one vendor. PEOs are deeply optimized for the US market — multi-state tax filing, IRS-certified payroll handling, group health insurance master plans. EORs don't do master-plan benefits at the PEO scale.

Cost comparison. PEO: $80–$220+ PEPM for US employees. EOR: typically 10–20% of gross salary as a fee, plus actual employment costs (employer-side taxes, benefits, etc.). For a $100K US employee, PEO costs $1,200–$2,600/year in PEPM. For a $100K international employee through an EOR, the EOR fee alone is $10K–$20K/year.

Common pattern: use both. A 50-person SaaS company with 35 US employees + 8 engineers in Poland + 4 in Brazil typically uses a PEO for the US team and an EOR for international. They're not redundant.

Full breakdown: PEO vs EOR.

An ASO (Administrative Services Organization) handles the same back-office functions as a PEO — payroll, benefits admin, HR compliance — but without the co-employment relationship. You keep your own EIN, your own group benefits, your own workers' comp policy. The ASO is a service vendor, not a legal co-employer.

When ASO wins:

• You have an existing benefits broker relationship and custom plan designs you can't replace
• You're large enough (typically 100+ EE) to negotiate competitive group rates on your own
• You want operational HR support without the PEO's benefits lock-in
• You're heading into M&A due diligence and PEO data fragmentation would complicate the process

When PEO wins:

• You're under 100 employees and small-group benefits rates are punishing
• You want master-plan buying power on health insurance and 401(k)
• You want a single-vendor relationship and the compliance liability transfer
• You operate in 3+ states and the multi-state filing complexity is real

Cost comparison. ASO: typically $30–$80 PEPM. Cheaper than PEO at headline, but you pay your own benefits at small-group rates (typically 15–30% higher than PEO master plan) and your own workers' comp at your standalone mod rate. ASO is rarely cheaper all-in for sub-100 EE companies in benefits-intensive industries.

Full breakdown: PEO vs ASO.

This is the long-arc question every growth-stage company faces: at what point do we stop renting HR and build our own team?

The cost math we walked through in our pricing guide: a 4-person in-house HR function (director + generalist + payroll specialist + benefits coordinator) runs $420K–$540K loaded, supporting 250–500 employees. PEO at mainstream PEPM costs roughly that for 250 employees. Crossover is around 250 EE.

But the math isn't the only consideration. Operational trade-offs:

• PEO wins on speed. Hiring an HR director + benefits manager + payroll specialist is a 6–9 month process. Switching on a PEO is 30–90 days.
• PEO wins on multi-state. Your in-house team becomes the multi-state compliance team. Building that depth takes years.
• In-house wins on flexibility. Your own team designs benefits to your culture, builds custom workflows, picks vendors that fit your stack.
• In-house wins on M&A readiness. Acquirers prefer companies with controlled HR data, their own benefits relationships, and no PEO transition hassle in due diligence.
• In-house wins on culture control. A PEO portal that says "PEO Metrics" on the W-2 is a small but constant signal that your company is small enough to outsource employment.

Most growth-stage companies use the PEO for years 2–5, then build in-house starting somewhere between 250–500 employees. The transition typically takes 12–18 months end-to-end.

The HR software stack is the DIY alternative to a PEO: HRIS + benefits broker + payroll provider + separate workers' comp + your own compliance management. You assemble the pieces; nobody assembles them for you.

Cost math for a 50-person company:

• Rippling alone (HRIS + payroll + benefits admin platform): $35–$50 PEPM ≈ $21K–$30K/year
• Benefits broker (cost built into premium but real): ~$5K–$15K/year equivalent
• Separate workers' comp policy at standalone mod rate: $8K–$25K/year
• Separate EPLI policy: $3K–$8K/year
• Your HR person's time managing it all: $30K–$50K of an HR generalist's annualized cost
• Total: $67K–$128K/year

Versus PEO at mainstream $145 PEPM for 50 employees: $87K/year all-in (after add-ons closer to $130K Year 1).

The stack can be cheaper, but typically only if you exclude the value of master-plan benefits buying power (15–30% lower health premiums) and pooled workers' comp (which matters more in some industries than others).

When the HR stack wins:

• Knowledge-work team (tech, professional services) where benefits aren't the biggest cost
• Low workers' comp risk (no field workers, no operational injuries)
• Tech-forward team that values modern UX and integrations more than service depth
• Single-state, no compliance complexity

When PEO wins:

• Benefits-intensive industries — small-group rates are punishing
• High workers' comp exposure — pooled mod is a real saver
• Multi-state operator — compliance offload is worth real money
• Want a single-vendor relationship

Full breakdown: PEO vs HR software stack.

Payroll-only providers — ADP RUN, Paychex Flex, Gusto (used solo, without the PEO bundle), QuickBooks Payroll — handle one specific thing: running payroll and filing taxes. They don't provide:

• Group health insurance (you bring your own broker and carrier)
• Workers' compensation (you bring your own policy)
• HR compliance support beyond basic
• Co-employment or liability transfer
• EPLI coverage

Cost. Typically $40–$60/month base + $4–$15 per employee monthly. For a 50-person company: ~$300–$800/month, $3,600–$9,600/year. Way cheaper than PEO ($87K+).

When payroll-only wins:

• You don't need group benefits (e.g., contractor-heavy team, or employees who prefer cash compensation)
• You already have a strong benefits broker delivering competitive group rates
• Single-state operation with simple compliance
• You're too small for PEO economics to pencil (under 5 employees)

When PEO wins:

• You want the bundle — benefits, workers' comp, compliance all under one vendor
• You want master plan group buying power
• You're multi-state and compliance offload is worth something
• You're 10+ employees and growing

The two often coexist: a 100-person company might use a payroll-only provider for contractors and a PEO for W-2 employees. Not redundant.

Full breakdown: PEO vs payroll company.

The honest decision tree, by company size:

Under 5 employees. Payroll-only provider. PEO economics don't pencil; ASO is overkill. Add a benefits broker if you offer health insurance.

5–25 employees. Default to PEO if you offer (or want to offer) group health insurance. The master plan buying power alone usually justifies the PEPM. If you have a strong existing broker and custom plan designs, ASO is reasonable.

25–100 employees, US-only. PEO is the most common right answer, especially in benefits-intensive or multi-state situations. HR software stack is viable for knowledge-work teams that want modern UX and tech integrations more than service depth.

100–250 employees. The middle band. PEO still usually wins, but the build-vs-rent calculation starts to surface. ASO becomes more viable. Some companies start hiring an HR generalist in-house and keep the PEO for benefits/compliance/payroll.

250–500 employees. Crossover zone. PEO and in-house both viable. The decision is usually about M&A readiness, benefits flexibility, and cultural control more than direct cost.

500+ employees. In-house HR almost always wins. The PEO economics deteriorate; you have the scale to negotiate competitive benefits and workers' comp directly.

Any size, hiring outside the US. EOR for international. Layer it with whatever you use for US (PEO, ASO, HR stack, in-house).

Industry overrides:

• Construction, manufacturing, trucking — PEO almost always wins (workers' comp pool dynamics)
• Tech, finance, professional services — PEO or HR stack both viable
• Healthcare — PEO usually wins (compliance complexity, multi-state)
• Restaurants and retail — PEO if multi-state, payroll-only if single-state and simple