Executives

Stephen J. Hemsley

Chief Executive Officer
UnitedHealth Group

Stephen Hemsley was named chief executive officer and president, UnitedHealth Group, on Nov. 30, 2006, and is a member of the company's board of directors. He previously served as president and chief operating officer, UnitedHealth Group. Hemsley joined the company in June 1997.

David S. Wichmann

Office of the Chief Executive
President
UnitedHealth Group

David Wichmann assumed the position of president, UnitedHealth Group, in November 2014. He has oversight responsibility for all of UnitedHealthcare's domestic and international businesses, and for overall UnitedHealth Group performance. Wichmann is a member of the Office of the Chief Executive and also served as chief financial officer of the enterprise from 2011 until mid-2016. He previously held positions as president, UnitedHealthcare; president and chief executive officer, Specialized Care Services (now OptumHealth); and senior vice president, Corporate Development. Prior to joining UnitedHealth Group in 1998, Wichmann was a partner with Arthur Andersen.

Larry C. Renfro

Office of the Chief Executive
Vice Chairman
UnitedHealth Group

Chief Executive Officer
Optum

Larry Renfro was named vice chairman, UnitedHealth Group, in November 2014, with oversight responsibility for all enterprise strategic relationships, key client relationships and companywide business growth efforts. He also serves as chief executive officer, Optum, UnitedHealth Group's health services platform, overseeing OptumInsight, OptumHealth and OptumRx. Renfro joined the company in January 2009 and has served as chief executive officer, Public and Senior Markets Group. He was formerly a senior executive officer at Fidelity Investments and a member of the Fidelity Executive Committee. He was president and chief executive officer, AARP Services, Inc., before he rejoined Fidelity in 2008. Renfro has also held senior executive positions at NewRiver, Inc.; State Street Bank & Trust; and Allmerica Financial.

John Rex

Office of the Chief Executive
Executive Vice President and Chief Financial Officer
UnitedHealth Group

John Rex was appointed executive vice president and chief financial officer of UnitedHealth Group and a member of the Office of the Chief Executive in 2016. Previously, Rex served as executive vice president, chief financial officer, Optum, UnitedHealth Group's health services platform, joining the company in 2012. Prior to Optum, Rex was a leading equity research analyst in the health care sector and managing director, J.P. Morgan. He also worked as a strategy and operations consultant, specializing in health services. A certified public accountant, Rex advised clients for Ernst & Young, where he also specialized in the health services sector.

Marianne D. Short

Office of the Chief Executive
Executive Vice President and Chief Legal Officer
UnitedHealth Group

Marianne Short was appointed executive vice president and chief legal officer, UnitedHealth Group, in January 2013, and was named to the Office of the Chief Executive in November 2014. She is responsible for overseeing legal, regulatory and compliance matters across the enterprise. Prior to joining the company, Short was the managing partner at Dorsey & Whitney LLP for six years, a partner in the Trial department, co-chair of the firm's Appellate and Health Litigation practice groups and a member of the American College of Trial Lawyers and the American Academy of Appellate Lawyers. From 1988-2000, she was a judge on the Minnesota Court of Appeals, authoring more than 900 opinions in virtually every area of civil and criminal law. She has more than 35 years of courtroom experience from her work on the court, the Dorsey firm and the Minnesota Attorney General's Office.

D. Ellen Wilson

Office of the Chief Executive
Executive Vice President, Human Capital
UnitedHealth Group

Ellen Wilson was appointed executive vice president, Human Capital, UnitedHealth Group, in June 2013, and was named to the Office of the Chief Executive in November 2014. She is responsible for overseeing all aspects of human resources, including compensation and benefits, talent management, leadership and employee development, rewards and recognition and organization development. Previously, Wilson served as chief administrative officer, Optum, guiding Optum's mission-critical business alignment and cultural programs. Prior to joining Optum, she served for 17 years at Fidelity Investments, concluding her tenure there as head of Human Resources.

Cory B. Alexander

Executive Vice President, External Affairs
UnitedHealth Group

Cory Alexander joined UnitedHealth Group in 2009 and oversees a number of key functions across the enterprise: government and public affairs, international relations, United Health Foundation and social responsibility efforts, the UnitedHealth Center for Health Reform and Modernization and enterprise government solutions and strategic relationships development. From 2006 to 2008, Alexander was vice president, Government and Industry Relations, Fannie Mae, and previously worked as chief of staff for House Democratic Whip Steny Hoyer (D-MD).

Terry M. Clark

Senior Vice President, Chief Marketing Officer
UnitedHealth Group

Terry Clark was appointed senior vice president and chief marketing officer, UnitedHealth Group, in 2014. Clark oversees branding, marketing and advertising for UnitedHealth Group and its two operating platforms, UnitedHealthcare and Optum, with responsibility for helping positively shape the customer experience. Previously, Clark served as chief marketing officer, UnitedHealthcare Medicare & Retirement, where he led marketing and direct-to-consumer engagement efforts focused on seniors. Clark joined UnitedHealthcare in 2006 from InterActiveCorp, a consumer technology company comprised of leading digital brands, where he served as executive vice president, sales and marketing, for the Entertainment Publications division.

Richard Migliori, M.D.

Executive Vice President, Medical Affairs and Chief Medical Officer
UnitedHealth Group

In 2013, Richard Migliori, M.D. was appointed executive vice president, Medical Affairs, and chief medical officer, UnitedHealth Group, working with businesses across the enterprise to help improve health care quality, access and affordability. Previously, as executive vice president, Health Services, Dr. Migliori was responsible for the ongoing development, design, and adaptation of market leading clinical innovations aimed at ensuring clinical excellence, improving clinical and economic outcomes, and delivering robust business performance on behalf of UnitedHealth Group's largest public and private sector clients.

Don Nathan

Senior Vice President and Chief Communications Officer
UnitedHealth Group

Don Nathan joined UnitedHealth Group as senior vice president, chief communications officer, effective May 2007. He is responsible for all internal and external communications. Nathan was formerly a strategic communications consultant with Robinson Lerer & Montgomery, beginning in 1991, and was a partner at the firm for 10 years. Previously, Nathan worked on Capitol Hill in Washington, D.C., serving in a number of congressional and campaign capacities.

John S. Penshorn

Senior Vice President
UnitedHealth Group

John Penshorn, senior vice president, has managed UnitedHealth Group's capital markets relationships since December 1998. Previously, Penshorn followed health services equities as a stock analyst at Piper Jaffray.

Jeannine M. Rivet

Executive Vice President
UnitedHealth Group

Jeannine Rivet was named executive vice president, UnitedHealth Group, in January 2001, and currently works with all company business segments in areas focused on strategic and business relationship management, customer and public relations, and nursing advancement. She has served as chief executive officer and president, Optum (now part of OptumHealth), chief executive officer, Ingenix, and chief executive officer, UnitedHealthcare. Before joining UnitedHealth Group, Rivet served as vice president, Group Operations, The Prudential Insurance Company of America.

Tom Roos

Senior Vice President and Chief Accounting Officer
UnitedHealth Group

Tom Roos was appointed chief accounting officer for the enterprise in August 2015. He is responsible for SEC reporting, accounting policy, tax and enterprise risk management. Previously, Roos was a partner at Deloitte & Touche LLP for eight years, where he worked closely with Deloitte & Touche's national office and industry leaders on emerging technical accounting and reporting matters in the health insurance industry, with experience in company mergers and acquisitions and initial public offerings.