Mark serves as Vice Chair of the Health & Human Resources Budget Subcommittee. His other committee assignments for the 85th General Assembly include- Human Resources, State Government, Veterans Affairs, and Labor.

Mark grew up in rural Imogene, graduating from Nishna Valley High School and the University of Northern Iowa in 1984. Mark was employed as a computer programmer/analyst with Garst Seed Company in Coon Rapids, IA for five years prior to returning to the family farm.

Mark and his wife, Rachel, were married in 2001 and have four children, Matthew, Julia, Peter and Ethan. The family resides on their farm in Mills County where they raise corn, soybeans and registered Simmental cattle. Rachel is a native of Lacona, IA and home schools and cares for the children. The Costello’s attend Sunnyside Bible Chapel in Atlantic.