Founded in 1976, Quest Diagnostics is one of the leading health care providers in the United States. Based in Madison, N.J., the company specializes in diagnostic testing, information and services. The main areas of expertise of the firm include health care solutions, lab tests, online services, clinical trials and medical research. It renders services like health plans, health/wellness programs, hospital options, pain management, transplant testing and other disease testing. College of American Pathologists (CAP) accredits the laboratories and facilities of Quest Diagnostics.