- Administaff is a publicly traded professional employer organization that provides human resources outsourcing to over 6,500 client companies and 110,000 employees across 50 states. - It offers a personnel management system that handles recruiting, performance management, training, benefits administration, payroll processing, and government compliance to reduce business owners' burdens and costs. - By co-employing clients' workers, Administaff can manage risks and liabilities on clients' behalf while providing valuable resources like an online employee service center and marketplace.