Does a PEO control my employees?

No. Co-employment lets a PEO handle back-office HR like payroll and benefits while you keep control of the work, your employees, and hiring and firing decisions.

Does a PEO replace my in-house HR team?

Usually not. A PEO works alongside your HR staff and takes on much of the day-to-day administration. Some very small companies use the PEO as their only HR support, but the strongest setups pair in-house HR with the PEO, and you stay in charge of your own team.

Who is responsible for compliance with a PEO?

Your business is, in the end. Helping you stay compliant is one of a PEO's main jobs, but the PEO is there to help you manage risk, not to absorb it for you.

How can I check a PEO's credentials?

Check the IRS list of certified PEOs (CPEOs) and ESAC's list of accredited PEOs yourself. In Colorado, a PEO must also be certified by the Colorado Department of Labor and Employment.

What Is a PEO? How Co-Employment Works

By Chris PetersonUpdated October 13, 2026

The short answer

A PEO, or professional employer organization, becomes a co-employer of your staff. It takes on the paperwork side of being an employer, like payroll, payroll taxes, benefits, workers' comp and HR compliance help, while you keep hiring, directing the work and running the business.

Do you feel bogged down by payroll, benefits and HR paperwork? You're not alone. HR is one of the most complex parts of running a company, and you have a business to run, people to manage and decisions to make. Even companies with an HR person on staff often lack the tools or expertise for the harder questions, like choosing a benefits package or keeping up with compliance.

Professional employer organizations have helped small companies handle HR for decades. Here's how they work.

What does a PEO do?

A PEO is an HR outsourcing arrangement built on co-employment. Its core job is providing employee benefits (health, dental, vision, life insurance, retirement plans) along with payroll, workers' compensation and the rest of the administrative HR work. A PEO also files payroll taxes and helps keep your company in line with state and federal employment rules, which is a lot for a small business to track on its own.

What is co-employment?

When owners first hear “co-employment,” it can sound like handing the reins of a company you built to someone else. It isn't. A PEO administers the employer side of HR. It doesn't manage your business.

The contract splits the employer role. The PEO pays wages from its own accounts, withholds and files payroll taxes under its own tax ID, and sponsors the benefits and workers' comp coverage. You still hire, set pay, direct the work, run the worksite and make the business decisions. Colorado law, for one, spells out this split for PEOs, which it calls employee leasing companies (C.R.S. 8-70-114).

One limit worth knowing: unless your PEO is IRS-certified (a CPEO), your business generally stays responsible for its federal employment taxes, whatever the contract says (IRS, 2026). A CPEO is solely liable for federal employment taxes on the wages it pays.

Who usually uses a PEO?

Mostly small companies. According to NAPEO, the PEO industry association, more than a third of PEO clients had fewer than 10 employees at the end of 2025, and the average client had about 23 (NAPEO, 2026).

What does a PEO not do?

It doesn't run your operations, decide who you hire, or take ownership of your company. Your business stays responsible for compliance in the end; the PEO's job is to help you get it right. For everything a PEO can take on, see Why Use a PEO? and What Services Does a PEO Offer?

Common questions

Does a PEO control my employees?: No. Co-employment lets a PEO handle back-office HR like payroll and benefits while you keep control of the work, your employees, and hiring and firing decisions.
Does a PEO replace my in-house HR team?: Usually not. A PEO works alongside your HR staff and takes on much of the day-to-day administration. Some very small companies use the PEO as their only HR support, but the strongest setups pair in-house HR with the PEO, and you stay in charge of your own team.
Who is responsible for compliance with a PEO?: Your business is, in the end. Helping you stay compliant is one of a PEO's main jobs, but the PEO is there to help you manage risk, not to absorb it for you.
How can I check a PEO's credentials?: Check the IRS list of certified PEOs (CPEOs) and ESAC's list of accredited PEOs yourself. In Colorado, a PEO must also be certified by the Colorado Department of Labor and Employment.