Yes. PEOs operate in all 50 states. Many states provide some form of specific licensing, registration, or regulation for PEOs. These states statutorily recognize PEOs as the employer or co-employer of worksite employees for many purposes, including workers' compensation and state unemployment insurance taxes. The IRS has recognized the right of a PEO to withhold and remit federal income and unemployment taxes for worksite employees per section 3511 of the IRS Code. The IRS has promulgated specific guidance confirming the authority of PEOs to provide retirement benefits to workers.

Business owners want to focus their time and energy on the "business of their business" and not on the "business of employment." As businesses grow, most owners do not have the necessary human resource training, payroll and accounting skills, the knowledge of regulatory compliance, or the backgrounds in risk management, insurance and employee benefit programs to meet the demands of being an employer. PEOs give small-group markets access to many benefits and employment amenities they would not have otherwise.

No. The PEO client/business owner retains ownership of the company and control over its operations. As co-employers, the PEO and client will contractually share or allocate employer responsibilities and liabilities per a client service agreement (CSA). The PEO will generally only assume responsibilities associated with a "general" employer for purposes of administration of benefits and remittance of payroll and payroll taxes. The client will continue to have responsibility for worksite safety and compliance. The PEO will be responsible for remittance of payroll and employment taxes, may maintain employee records and may retain a limited or general right to hire and fire, as delineated in the CSA. Because the PEO also may be responsible for providing access to workers' compensation coverage, many PEOs also focus on and provide assistance with safety and compliance. In general terms, the PEO will focus on employment-related issues, and the client will be responsible for the actual business operations.

PEOs do not supply labor to worksites. PEOs supply services and benefits to a business client and its existing workforce. PEOs enter into a co-employment arrangement typically involving all of the client's existing worksite employees and sponsor benefit plans for the workers and provide human resources services to the client. In most cases, the PEO provides access to health insurance, retirement savings plans, and other critical employee benefits for the worksite employees of the business client. If a PEO relationship is terminated, the worksite employees’ co-employment arrangement with the PEO ceases, but they will continue as employees of the client.

By comparison, a leasing or staffing service supplies new workers, usually on a temporary or project-specific basis. These leased employees return to the staffing service for reassignment after completion of their work with the client company. Some define employee leasing as a temporary employment arrangement where one or more workers selected by the leasing or staffing entity is assigned to a customer frequently for a fixed period of time or for a specific project. Upon termination of the staffing or leasing company arrangement, the worker has no continuing employment relationship with the client.

Historically, leasing terminology was used to describe what has evolved into PEO relationships. Some older state statutes governing PEOs still use the leasing terminology, contributing to the confusion about PEOs.

Like a leasing situation, a temporary staffing service recruits and hires employees and assigns them to clients to support or supplement the client's workforce in special work situations, such as employee absences, temporary skill shortages or seasonal workloads. These workers are traditionally only a small portion of the client's workforce.

PEOs do not supply labor to worksites. They co-employ existing permanent workforces and provide services and benefits to both the worksite employer and the employees.

PEOs provide services to between 156,000 and 180,000 small and mid-size businesses, employing between 2.7 and 3.4 million people.

​A PEO's economy of scale enables each client company to lower employment costs and increase the business's bottom line. The client can maintain a simple in-house HR infrastructure or none at all by relying on the PEO. The client also can reduce hiring overhead. The professionals at the PEO can provide critical assistance with employer compliance, which helps protect the client against liability. In many cases, the client can pay a small up-front cost for a significant technology and service infrastructure or platform provided by the PEO. In addition, the PEO provides time savings by handling routine and redundant tasks for its clients. This enables the business owner to focus on the company's core competency and grow its bottom line.