Sierra Health Services, Inc.

Sierra Health Services, Inc., based in Las Vegas, is a diversified healthcare services company that operates health maintenance organizations, indemnity insurers, preferred provider organizations, prescription drug plans and multi-specialty medical groups. Sierra's subsidiaries serve over 870,000 people through health benefit plans for employers, government programs and individuals. On March 11, 2007, Sierra entered into an Agreement and Plan of Merger (Merger) with UnitedHealth Group Incorporated, a Minnesota corporation. The merger has received approvals from California, Arizona and Nevada and is awaiting clearance from the Department of Justice Antitrust Division under the Hart-Scott-Rodino Act. For more information, visit the Company's website at www.sierrahealth.com. Sierra Health Services, Inc. operates as a subsidiary of UnitedHealthcare, Inc.