After graduation, Costello joined the United States Air Force, from 1974 to 1977, serving as a Captain, and then returned to Florida in 1977, settling in Ormond Beach and practicing dental medicine.

Advancing to the general election, Costello campaigned on "creating jobs for Floridians in renewable-energy research development and manufacturing," and was opposed by Tim Huth, the Democratic nominee and the former Deputy Superintendent of Volusia County Schools.

He faced former federal prosecutor Ron DeSantis, restaurant executive Craig Miller, St. Johns County School Board member Beverly Slough, Jacksonville City Councilman Richard Clark, William Billy Kogut, and Alec Pueschel in the Republican primary.

[4] Costello won the Republican primary unopposed, and faced Noel Bickford, a retired healthcare executive and the Democratic nominee, in the general election.

He campaigned on promoting job creation, increasing protection of the environment, and preserving home rule of local governments, as his work was not done in elected office, declaring, "I never intended to get out of politics.

Costello's campaign theme — "Fred stands for US" — emphasized years of public elected and volunteer service as a local leader attending to the issues of his constituents in the community.