Kooyenga moved to
Milwaukee in 2001, passed the
Certified Public Accounting exam, and began working for accounting firm
KPMG. He worked at KPMG as a
senior manager until 2011. Kooyenga then served as
chief financial officer for Milwaukee-based
information technology services and consulting firm Mpirik starting in January 2015, a role he served in until May 2017. From June 2019 until the present day, Kooyenga has served as a board member and consultant for Alligator Holdings,
U.S. Army In 2005, Kooyenga and his two brothers joined the
United States Army, a decision they made as a result of the
terrorist attacks of September 11, 2001. He attended the
United States Army's basic training, the
Officer Candidate School and the Military Intelligence Officer Course. After completing the year-long Army training, Kooyenga returned to his career in public accounting. Kooyenga was deployed to active duty in Iraq from January 2008 to November 2008. Although trained as a Military Intelligence Officer, Kooyenga was assigned as the
4th Infantry Division's Officer in Charge of Economic Development in
Baghdad, Iraq. Kooyenga was awarded the
Bronze Star for his service. Kooyenga still serves in the U.S. Army Reserve and, in June 2022, was selected for the rank of
lieutenant colonel.
Political career In Fall 2010, Kooyenga was elected to represent the 14th District for the
Wisconsin State Assembly. He was sworn into office on January 3, 2011. Kooyenga endorsed
Mitt Romney in the 2012 presidential election. During his time in the Assembly, Kooyenga emerged as a conservative star as part of the "CPA Caucus," a group of four certified public accountants in the Assembly who specialized in analyzing state finances. Kooyenga later praised the UW System for voluntarily freezing tuition for another year. In May 2017, Kooyenga removed a protester's sign, which had a valid permit, from a public area of the Wisconsin State Capitol which was critical of President Donald Trump and Republicans. The owner filed a lawsuit against Kooyenga and the State of Wisconsin for violating his
First Amendment rights, which led to the State paying him $30,000 to settle the lawsuit in April 2018. Kooyenga repaid the $30,000 to the state in July 2018. Kooyenga announced his campaign for
Wisconsin State Senate's 5th District in September 2017, seeking to fill the seat left vacant by
Leah Vukmir, who was running for the
U.S. Senate. He won the November 2018 election with 51.15% of the vote against Democratic opponent Julie Henszey. During his time in the Senate, Kooyenga worked on a range of issues related to education, tax cuts and budgeting,
professional licensure and healthcare. In August 2019, he and Republican
Amy Loudenbeck introduced telehealth legislation that was signed into law months before the
COVID-19 pandemic began. As a member of the Joint Committee on Finance, Kooyenga also assisted in writing the 2021–2023 state budget and argued for conservative tax policy, including tax cuts. In 2021, he introduced bipartisan legislation in the Wisconsin legislature to introduce
ranked-choice voting (RCV). He argued that RCV would reduce
polarization and extremism by removing incentives for legislators to cater to extremist elements within their parties. He also introduced an amendment to the state constitution to return oversight of federal funding to the state legislature as well as legislation to clean up industrial pollutants from the Milwaukee Estuary. In April 2022, Kooyenga announced he would not seek re-election to the State Senate, citing his commitments to the U.S. Army, his private sector career, and his four children as reasons for stepping down from public service.
Metropolitan Milwaukee Association of Commerce After leaving office, Kooyenga was selected as president of the Metropolitan Milwaukee Association of Commerce, the main business advocacy organization for Milwaukee, Waukesha, Ozaukee, and Washington counties. In April 2025, Kooyenga made headlines in Wisconsin when he spoke out against the new
tariffs imposed by U.S. president
Donald Trump, calling it "one of the largest tax increases in U.S. history". He also noted that business leaders were "scared" of speaking out and feared retaliation from the Trump government. ==Electoral history==