Michael B. McCallister was Chairman of the Board of Humana Inc. (a health care company in Louisville, Kentucky) from 2010 to December 31, 2013, having also served as Chief Executive Officer of Humana from 2000 until his retirement in 2012. During Mr. McCallister's tenure, he led Humana through significant expansion and growth, nearly quadrupling its annual revenues between 2000 and 2012, and led the company to become a FORTUNE 100 company. Mr. McCallister received his B.S. in accounting from Louisiana Tech University and earned his M.B.A. in finance from Pepperdine University. Mr. McCallister is a Director of AT&T, Fifth Third Bancorp and Zoetis Inc. He previously served as a Director of Humana Inc. (2000-2013) and Chairman of the Health and Retirement Task Force at Business Roundtable.