Professional Employer Organization
A PEO enters a co-employment relationship with your business. The PEO becomes the employer of record for tax and benefits purposes, giving you access to a full carrier market for benefits, workers’ comp master policies, and shared compliance infrastructure. You retain full control of day-to-day operations, hiring, and management.
Best for: Businesses that want full-service HR with maximum benefits buying power and shared compliance liability.
- Full carrier market shopped for your group
- Workers’ comp master policy
- Shared compliance liability
- All-in-one bundled service
Administrative Services Organization
An ASO provides HR administration, payroll processing, and compliance support without a co-employment relationship. Your business remains the sole employer of record. The ASO handles the administrative work under your company’s tax ID and policies. You choose which services to use and retain complete control over benefits, workers’ comp, and vendor relationships.
Best for: Businesses that want expert HR administration while maintaining sole employer status and maximum flexibility.
- Full control of employer-of-record status
- Modular service selection
- Choose your own benefits carriers
- Maximum vendor flexibility
At VertiSource HR, you get the same team, same technology, and same service quality regardless of which model fits your business.
What the data says about PEOs specifically.
Not VertiSource HR internals. Industry-wide figures published by the National Association of Professional Employer Organizations.
How PEO and ASO stack up.
A detailed feature comparison to help you evaluate the right model. PEO, ASO, or DIY.
| Feature | PEO | ASO | DIY / In-House |
|---|---|---|---|
| Employer of Record | Shared (co-employment) | Your company only | Your company only |
| Tax ID for Filings | PEO’s FEIN (or shared) | Your company’s FEIN | Your company’s FEIN |
| Payroll Processing | Included | Included | Manage or outsource separately |
| Tax Filing & Compliance | PEO handles under their FEIN | ASO handles under your FEIN | Manage or outsource separately |
| Benefits Access | All carriers shopped for your group | ASO helps administer your plan | Source and administer independently |
| Benefits Buying Power | Full carrier market shopped for your group | Small-group rates (your company only) | Small-group rates (your company only) |
| Workers’ Comp Coverage | PEO’s master policy (pay-as-you-go) | Your own policy (ASO may administer) | Your own policy |
| Workers’ Comp Claims | PEO manages claims | ASO may assist | You manage or hire a TPA |
| HR Compliance Support | Shared liability with PEO | Advisory support (liability stays with you) | Full liability on your company |
| HRIS / HR Technology | Platform included | Typically included | Purchase separately |
| Day-to-Day HR Support | Dedicated HR specialist | Dedicated HR specialist | Hire in-house HR staff |
| Service Bundling | All-in-one bundle | Modular: pick the services you need | Assemble your own vendor stack |
| Vendor Flexibility | Limited (PEO provides the stack) | High (choose your own carriers) | Full flexibility |
| Typical Cost | $40–$160/employee/month or 2%–6% of payroll | Lower admin fees, but you fund benefits/WC separately | Sum of all vendor costs + internal HR salary |
| Best Suited For | 15–150 employees wanting coverage and market leverage | 50–500 employees wanting admin support with sole-employer status | Businesses with dedicated in-house HR teams |
Exact features and scope vary by provider. At VertiSource HR, both PEO and ASO clients receive a dedicated HR specialist and full access to our HR Cloud platform.
PEO if you want maximum benefits leverage and shared liability.
Teams of 15 to 150 employees that would rather offload the employer-of-record administrative weight and have us shop the full carrier market for benefits usually land here. You keep operational control; the PEO takes the tax FEIN, runs payroll under it, and carries the master workers’ comp policy. You get competitive group rates you couldn’t reach standalone.
About 80% of the small businesses we match to a model end up on the PEO side. The market leverage and shared compliance liability are the two reasons.
- You want the full carrier market shopped for your benefits
- Workers’ comp is a pain point or major cost
- You are comfortable with co-employment for admin
- Multi-state complexity is real and growing
- You want one bundled invoice, not a vendor stack
ASO if you need admin support but want to stay sole employer.
Teams of 50 to 500 employees that already run a solid benefits plan, don’t want to move the FEIN, or have vendor relationships worth keeping usually land on ASO. You keep full employer status; we handle the payroll processing, tax admin, compliance support, and HR advisory work under your FEIN.
ASO also fits companies that expect to scale past the PEO sweet spot, or industries where co-employment doesn’t clear legal review.
- Sole employer of record is a hard requirement
- You already have strong carrier relationships
- Vendor flexibility matters more than bundling
- You expect to scale past the PEO band
- Modular services fit better than all-in-one
Not sure which model fits? Take the assessment.
Answer 6 quick questions. Get a personalized recommendation with the reasoning behind it.
How many W-2 employees does your company have?
Include all full-time and part-time employees on payroll.
In how many states do you have employees?
Multi-state operations add payroll tax and compliance complexity.
How do you currently handle employee health benefits?
How would you describe your workers’ compensation situation?
How confident are you in your company’s HR compliance posture?
How important is it that your company remains the sole employer of record?
In a PEO arrangement, the PEO becomes a co-employer for tax and benefits purposes. You still retain full operational control.
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PEO & ASO: clearing up the common confusion.
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