You can outsource HR without co-employment by using a managed service provider, which runs the work while your company remains the sole employer. If you’ve searched this question already, you’ve probably noticed that most of the answers come back describing a PEO, which is the one model that does co-employ.
This article explains what co-employment actually is, why a PEO needs it, what the alternative looks like, and which model the data says fits which size of company.
Key takeaways
- Co-employment defines the PEO model specifically, rather than HR outsourcing as a whole.
- Under a managed service model your company stays the employer of record and keeps the employment relationship.
- NAPEO’s own 2025 data shows 85 percent of PEO clients have fewer than 50 employees, and 6 percent have 100 to 499.
- A managed provider can run payroll, benefits administration and your HCM platform without any change to who employs your staff.
The Short Version
If you want the administrative work gone but your company to remain the employer, you want a managed service provider, not a PEO.
| PEO | Managed Service | |
|---|---|---|
| Who employs your staff | Co-employer with you | Your company only |
| Employer of record | The PEO | Your company |
| Benefits sourcing | The PEO's master plan | Your plans, administered for you |
| Payroll tax filing | Under the PEO's EIN | Under your EIN |
| Who runs your HCM platform | Usually the PEO's own system | Your platform, operated for you |
On this page
- What co-employment actually means
- Why does a PEO require it?
- What you keep, and what changes
- Can you outsource HR without co-employment?
- How the managed service model works
- Who is each model actually built for?
- Do you lose control of your employees?
- The alternatives side by side
- How do you move off a PEO?
- Frequently asked questions
What co-employment actually means
Co-employment is a contractual arrangement in which a professional employer organization becomes a joint employer of your staff for administrative and tax purposes. Your employees appear on the PEO’s payroll filings, and the PEO sponsors their benefits, while you continue to direct their day to day work.
Co-employment is not a merger, and it isn’t a transfer of your workforce. Your people still work for you, in your building, on your objectives. What changes is the administrative and tax identity attached to their employment. That distinction is precise, and it’s worth getting right, because it’s the single fact that separates the models.
Why does a PEO require it?
A PEO needs co-employment because it files payroll taxes and sponsors benefits under its own employer identification number. To do that lawfully it has to stand in an employment relationship with the people it’s filing for.
That structure is what generates the PEO’s main advantages. Pooling many client companies under one master health plan gives a small employer access to benefits pricing and workers’ compensation terms it could not obtain alone. The co-employment relationship is the mechanism that makes the pooling possible, which is why you can’t have the pooled pricing without it. Our comparison of an HRO versus a PEO covers how the two structures differ in practice.
What you keep, and what changes
Under a PEO, you keep day to day direction of your employees, including who you hire, how you manage them and whether they stay. The PEO becomes the administrative employer of record, which is a different thing from operational control.
What changes is more subtle than most buyers expect. Your benefits move onto the PEO’s plan, so plan design and carrier choice are no longer entirely yours. Your payroll tax filings carry the PEO’s identity. And your exit is more complex, because leaving means re-sourcing benefits under your own plans rather than simply changing vendors.
Can you outsource HR without co-employment?
Yes. A managed service provider performs the same administrative work under a service contract rather than a co-employment agreement, so your company remains the sole employer throughout.
The work is largely identical from your side of the desk. Payroll gets processed, benefits get administered, employees get someone to call, compliance administration gets handled. What differs is the legal structure underneath it: a vendor relationship rather than a shared employment relationship. Corban’s PEO alternative page sets out how that arrangement is scoped.
How the managed service model works
A managed provider runs payroll, benefits administration, employee support and your HCM platform as your vendor, under a defined scope of work. Your employer identification number stays on the filings. Your benefits stay on your plans. Your employees stay solely yours.
Practically, the provider works inside your systems rather than moving you onto theirs. Payroll runs in your instance of the platform you already own, benefits are administered against your existing carriers, and employee questions route to the provider’s service team rather than to your HR generalist.
Who is each model actually built for?
The clearest answer to this comes from the PEO industry’s own research rather than from anyone selling an alternative. The National Association of Professional Employer Organizations publishes a periodic analysis of who its members actually serve.
How we researched this
The figures below are from NAPEO, PEO Clients: 2025, published October 2025 and drawn from more than 50,000 PEO client records covering 2023 to early 2025. The percentages are NAPEO’s own. The under-50 total is our sum of its four smallest size bands. We verified every figure against the source document in August 2026. NAPEO is the trade association for the PEO industry, so these numbers come from a source with no interest in understating the model’s reach.
| Client Size | Share of All PEO Clients |
|---|---|
| 1 to 4 employees | 16% |
| 5 to 9 employees | 19% |
| 10 to 19 employees | 24% |
| 20 to 49 employees | 26% |
| 50 to 99 employees | 9% |
| 100 to 499 employees | 6% |
| 500 or more employees | Under 0.5% |
Add the top four bands and 85 percent of PEO clients have fewer than 50 employees. Six percent have 100 to 499, and fewer than half a percent have 500 or more. NAPEO also reports overall penetration of 14 percent among employers with 20 to 499 employees, peaking at 15 percent among those with 50 to 99, and describes the PEO sweet spot as businesses with between 20 and 499 employees.
Set those bands against your own size. The PEO’s pooling and pricing were built for companies well below a typical mid-market employer. That doesn’t make it a bad model. It makes it a model whose core advantage, pooled benefits pricing, weakens exactly as your own purchasing power strengthens.
Do you lose control of your employees?
No. Under a managed service agreement your company remains the sole employer and retains the employment relationship in full, including hiring, management, compensation decisions and termination.
This question comes up constantly, and it’s worth answering precisely rather than reassuringly. Even under a PEO, you direct your employees day to day. The accurate distinction between the models isn’t control of people, it’s the employment and tax identity attached to them. We cover the question in more depth in our note on whether outsourcing means losing control of employees.
The alternatives side by side
Four models compete for this decision, and only one of them changes who employs your staff. A PEO co-employs. An ASO performs the administration without co-employment. An HRO takes over defined functions under contract. A fully managed service does the same and also operates your HCM platform.
NAPEO reports that businesses using a PEO grow two times faster, have employee turnover 12 percent lower and are 50 percent less likely to go out of business than comparable businesses that don’t. Those are meaningful findings and they belong in an honest comparison. They also describe a client base that is, on NAPEO’s own numbers, overwhelmingly under 50 employees. For a fuller breakdown of the three named models, see the difference between an HRO, a PEO and an ASO.
How do you move off a PEO?
Moving off a PEO is staged across a quarter, with benefits renewal and payroll cutover planned before anything changes. It’s more involved than switching a normal vendor, because your benefits currently sit on the PEO’s master plan and have to be re-sourced under your own.
A workable sequence runs: re-source benefits with your broker, establish your own payroll tax registrations if they lapsed, run a parallel payroll cycle against the PEO’s, then cut over at a clean period boundary, ideally aligned to your benefits renewal date. Anyone who tells you this happens in two weeks is describing a risk. Our PEO transition guide covers the sequence in detail.
FAQ
Co-employment means two organizations share the legal employer relationship for the same worker. In a PEO arrangement, the PEO handles payroll tax filing and benefits sponsorship under its own identification number, while your company continues to direct the employee’s work. Both parties are employers for different purposes.
No. A PEO is one type of HR outsourcing, distinguished by co-employment. Other models, including ASO, HRO and fully managed services, perform comparable administration under a service contract while your company remains the sole employer.
Your company. Under an HRO or managed service arrangement, the provider acts as a vendor performing administration on your behalf, and your organization remains the employer of record with payroll taxes filed under your own identification number.
Yes, and it’s the part to plan first. Because benefits are sponsored through the PEO’s master plan, leaving requires sourcing your own plans, usually through a broker, and timing the change to a renewal so employees aren’t moved mid year.
Yes. A managed provider processes payroll on your behalf under your own employer identification number, as a service rather than as a joint employer. The filings, the liability and the employment relationship remain with your company.
Talk to Corban OneSource
Schedule a consultation to talk through who runs your platform today.
Related Reading
Disclaimer
This article explains how the models are structured and is not legal advice; consult your own counsel on your specific circumstances.
Connect with us to learn more about HR Outsourcing!
