The Principal Financial Group Announces Agreement to Acquire Diversified Dental Services

The Principal Financial Group®, the nation's premier provider of employee and voluntary benefits, announces a strategic agreement to acquire Diversified Dental Services, Inc., a Nevada-based independent dental preferred provider organization (PPO). The transaction is expected to close on Oct. 1, 2007. "The acquisition of Diversified Dental Services furthers our national dental network strategy of offering more providers and better pricing for members and business partners,” said Deanna Strable, senior vice president of the Specialty Benefits Division of The Principal®. "Diversified Dental Services brings a proven track record of building and growing regional networks. We look forward to using their experience to continue expanding our owned network coverage.” Diversified Dental Services, Inc. contracts with more than 1,500 dentists in Nevada and parts of Utah, California, Arizona, Mississippi and Tennessee to offer discounts to PPO members who obtain dental care from a network dentist. The dental PPO will continue to be available through employers, insurance companies and associations, often combined with a dental benefits plan. The Principal currently operates a national dental network with more than 76,000 providers across 37 states, plus the District of Columbia. "The Principal Financial Group has a strong reputation in the dental industry, making it a good fit for our customers," said Dan Volle, president, Diversified Dental Services, Inc. "With this agreement, Diversified Dental Services, Inc. can now better serve new and existing customers with more products, services and support.” Bruce Hentschel, dental managed care director for The Principal, commented, "Ultimately our extensive network agreements allow us to drive greater value for our members, which encourages them to seek routine dental exams to improve both oral and overall health. We continue to look for new ways to bolster our networks and provide innovative products and services for our customers.” The Principal recently introduced a Principal Dental Series II, one of the most flexible dental products in the market. To learn more about dental solutions offered by The Principal, brokers should contact their Principal Financial Group representative or visit www.principal.com. About Diversified Dental Services Diversified Dental Services, Inc. is an independent dental preferred provider organization serving all of Nevada and parts of Utah, California, Arizona and Mississippi and Tennessee. Through contracts with dentists, Diversified Dental Services, Inc. provides clients dental services at a discounted rate. Diversified Dental Services, Inc. contracts with more than 1,500 individual dentists for general dentistry, endodontics, oral surgery, orthodontia, pediatric dentistry, periodontics and prothodontics. About the Principal Financial Group The Principal Financial Group® (The Principal ®)1 is a leader in offering businesses, individuals and institutional clients a wide range of financial products and services, including retirement and investment services, life and health insurance, and banking through its diverse family of financial services companies. A member of the Fortune 500, the Principal Financial Group has $282.1 billion in assets under management2 and serves some 18.1 million customers worldwide from offices in Asia, Australia, Europe, Latin America and the United States. Principal Financial Group, Inc. is traded on the New York Stock Exchange under the ticker symbol PFG. For more information, visit www.principal.com. Insurance products and services issued by Principal Life Insurance Company. 1 "The Principal Financial Group" and "The Principal” are registered service marks of Principal Financial Services, Inc., a member of the Principal Financial Group. 2 As of June 30, 2007