The three-member Iowa Utilities Commission is the policymaking body for the agency. IUC Commissioners are appointed by the governor and subject to confirmation by the senate.
Staggered six-year terms generally begin on May 1. Vacancies are filled for the unexpired portion of the term in the same manner as full-term appointments are made. Subject to confirmation by the senate, the governor also appoints a member as the Commission Chair of the IUC. The chairperson serves as the administrative head of the agency for a two-year term that begins and ends as provided in Iowa Code § 69.19.
Sarah M. Martz, Chair
Sarah M. Martz began her service on May 1, 2023, to fill the remainder of a term that runs through April 30, 2027. Gov. Kim Reynolds appointed Martz as Commission Chair on May 19, 2025.
Martz serves on the Committee on Energy Resources and the Environment for the National Association of Regulatory Utility Commissioners (NARUC) and the NARUC State Working Group on Transmission, and participates in the NARUC and National Association of State Energy Officials initiative "Comprehensive Electricity Planning in an Era of Load Growth." Martz served as the Iowa representative to SPP's Regional State Committee (RSC) from 2023 to 2025. She began serving as the Iowa representative to the Organization of MISO States (OMS) in 2025.
She previously worked at Alliant Energy/Interstate Power and Light Company (IPL) for 11 years in various roles: including optimizing power plants, researching solar performance in the Midwest, and piloting new technologies such as energy storage in Iowa communities. She also managed the electrical distribution engineering team for IPL. In 2022 she became Director of Engineering for the distribution system at Iowa State University's utility. She has managed large diverse teams of technical staff and has been involved with electric, gas, heating/cooling, and water utilities over her career.
Martz earned a bachelor's degree in Mechanical Engineering from Iowa State University and a Master's degree in Mechanical & Aerospace Engineering from the University of California, Irvine, and she holds a professional engineering license.
She and her husband live in Ames with their three children.
Joshua J. Byrnes, Commissioner
Joshua Byrnes is serving a six-year term that runs May 1, 2025, through April 30, 2031. He was originally appointed by Governor Reynolds effective December 14, 2020, to fill the remainder of a term that ran through April 30, 2025.
Byrnes serves on the National Association of Regulatory Utility Commissioners (NARUC) Gas-Electric Alignment for Reliability Task Force. Byrnes also sits on the NARUC Executive Committee as treasurer, is a member of the Committee on Gas and the Task Force on Natural Gas Resource Planning, serves on the Executive Committee of the Mid-America Regulatory Conference (MARC), and is the immediate past president of the Organization of MISO States (OMS). He began serving as the Iowa representative to the Southwest Power Pool Regional State Committee in May 2025.
Byrnes previously was General Manager of Osage Municipal Utilities and served six years in the Iowa House of Representatives, where he was Iowa House Transportation Chairman. He also had been appointed by Governor Reynolds to serve on the Iowa State Board of Education. He is a former CUSB Bank director and also has served on the Iowa Association of Municipal Utilities Board of Directors, American Public Power Associations DEED Board.
He attended Riceville public schools and received his Bachelor of Arts degree in biology from Luther College in Decorah and his Master of Science degree in Educational Leadership from Winona State University in Minnesota. He also took PhD coursework at Iowa State University.
He and his wife reside in rural Mitchell County and enjoy hobby farming along with their three children.
Jon Dunwell, Commissioner
Jon Dunwell was appointed by Gov. Kim Reynolds on October 5, 2026, to fill the remainder of a term that runs through April 30, 2029.
Dunwell is a former state legislator who served in the Iowa House representing District 38, covering parts of Jasper County, from October 2021 through October 2026. During his tenure, he served as an Assistant Majority Leader. He also served as Vice Chair of the Administration and Rules Committee and Vice Chair of the Administration and Regulation Appropriations Subcommittee. He was a member of several legislative committees, including Agriculture, Environmental Protection, Judiciary, Local Government, State Government, and Transportation. Additionally, he served on the joint International Relations Committee.
Beyond the legislature, Dunwell's diverse professional career includes experience as an executive coach and vice president of a national financial services firm. He has an extensive background in pastoral ministry, holding pastorates in Minnesota, Florida, and Iowa. Additionally, he served as the senior chaplain for the Orange County Sheriff’s Office in Orlando, Florida. Most recently, he served as the Director of Outreach and Engagement at The FAMiLY Leader.
He earned a bachelor’s degree in Pastoral Ministries, receiving his education from Bethany Global University and Crown College in Minnesota. He and his wife, Christine, have two grown sons, Addison and Bryce.
Communications Reminder
Any communications with individual members of the Iowa Utilities Commission on material issues in contested cases pending before the Commission may constitute a prohibited ex parte communication per Iowa Code § 17A.17. If you wish to comment on the record on a pending matter, the comments must be filed in the docket. You can do that by submitting written comments, objections, or letters of support on this Comments and Objections Form, which also can be found in the IUC's electronic filing system (EFS). You can also submit written comments via EFS under the Submit tab. Select "Submit Filing" and "Submit Filing As Guest," then complete the form. Comments made directly to Commissioners will not be filed in a docket or become part of the record. If you have a complaint or inquiry about a utility, contact IUC Customer Service at 877-565-4450 or [email protected].