A PEO (Professional Employer Organization) enables clients to outsource human resource management, payroll administration, benefits, and workers' compensation to focus on their core business. There are over 700 PEOs in the United States serving around 2-3 million employees. While all PEOs provide these services, they differ in areas like size, geographic coverage, accreditation, and risk management approach. PEOs allow clients to cost-effectively comply with regulations and take advantage of solutions like group benefit plans and strategic alliances between PEOs and brokers.