Tandem HR is a rapidly growing HR outsourcing company headquartered in Westchester, Illinois. Also known as a professional employer organization (PEO), Tandem HR provides high-touch HR services to hundreds of thousands of worksite employees across the nation. Tandem HR is recognized by the Internal Revenue Service (IRS) as a Certified Professional Employer Organization (CPEO). The Employer Services Assurance Corporation (ESAC) is to the PEO industry what FDIC is to the banking industry. Our clients and their fiduciaries are uniquely protected by our ESAC certification status. Reach out to us today to see if we're a good fit for your growing organization!