Rear Adm. Guadagnini graduated with distinction from the U.S. Naval Academy in 1980, earning a Bachelor of Science in Economics. After a brief tour with the Navy Fighter Weapons School, he entered flight training, earning his wings in 1982.

Operationally, he has served as a division officer in Attack Squadron VA-65, on the staff of Carrier Air Wing 8 as head landing signal officer and strike operations officer, as head of the safety and maintenance departments in VA-65, and as operations officer for Carrier Strike Group 8. He commanded Strike Fighter Attack Squadron 15 from 1997 to 1998, and Carrier Air Wing 17 from 2004 to 2005. During these operational tours he operated from the decks of 12 different aircraft carriers, participating in combat Operations Desert Storm, Provide Comfort, Deliberate Force, Southern Watch, Enduring Freedom, and Iraqi Freedom.

Shore duty assignments include three years as a test pilot and instructor at the Naval Test Pilot School, a Legislative Fellowship in the United States Senate, and as an aide and flag lieutenant in the Bureau of Naval Personnel and on the Commander in Chief, U.S. Pacific Fleet staff in Hawaii. Guadagnini also worked as a liaison between the Office of the Secretary of Defense and the U.S. Congress, and served in the Navy Personnel Command as the division director for Aviation Officer Distribution.

As a flag officer, Guadagnini commanded Carrier Strike Group NINE, served as the chief of Naval Air Training; head of Human Resources for the Naval Aviation Enterprise; Deputy Commander for Fleet Management at U.S. Fleet Forces Command; and, is currently the director, Maritime Headquarters at U.S. Fleet Forces Command.

Guadagnini has over 4,700 hours of flight time in 52 different aircraft. His awards include two Battle E's. He has flown 95 combat missions.