CoreSource is a third party administrator (TPA) of employee benefits programs. As a TPA, it manages the health insurance benefits of self-insured employers and their workers throughout the US. Among other services, the company handles claims, provides access to nationwide and specialty provider networks, and manages a variety of ancillary benefit programs, such as dental and vision coverage, flexible spending accounts, and short-term disability insurance. It serves some 700 clients, mostly mid-sized and large corporations, representing about 2.5 million employee members. It operates from about 15 offices located across the country.