Sen. Joni Ernst (R-Iowa) announced on Sept. 2, 2025, that she will not seek re-election to the U.S. Senate in 2026.

On her retirement, Ernst said, “I never imagined this farm girl would have the opportunity to serve as a lieutenant colonel and then a United States senator. […] While this chapter of elected service will soon close, I will always find ways to best serve my community, state and these great United States of America.”

In 2014, Ernst ran for her first term representing Iowa in the U.S. Senate after then-Sen. Tom Harkin (D-Iowa) announced he would not seek re-election. Ernst was one of nine Republicans to win a Democratic-held U.S. Senate seat in a general election that year. In the general election, she defeated Bruce Braley (D) 52% to 44%. Ernst won re-election in 2020, defeating Theresa Greenfield (D) 52% to 45%.

As of Sept. 2, 2025, independent race forecasters The Cook Political Report, Inside Elections, and Sabato’s Crystal Ball have rated the general election for the seat as Likely Republican.

CBS News’ Kaia Hubbard wrote, “Ernst’s decision not to seek reelection opens up a seat in Iowa, where Democrats are hoping to make inroads as the party seeks to take control of the Senate in the midterm elections. But a Democratic candidate would face steep odds in a state [Donald Trump] won by more than 13 points in 2024, and Iowa hasn’t elected a Democrat to the Senate since 2008.”

As of Sept. 2, 2025, Ernst is one of 33 members of the U.S. Congress—eight U.S. Senate members and 25 U.S. House members—who have announced they will not seek re-election to their current seats in 2026.

Of the senators not running for re-election, seven—Ernst, Thom Tillis (R-N.C.), Dick Durbin (D-Ill.), Jeanne Shaheen (D-N.H.), Mitch McConnell (R-Ky.), Tina Smith (D-Minn.), and Gary Peters (D-Mich.)—announced their retirements from public office, while the other—Sen. Tommy Tuberville (R-Ala.)—is running for governor of Alabama.

Compared to the last four election cycles, there were five retirement announcements at this point in 2024, five in 2022, four in 2020, and one in 2018.

Between January 2011 to September 2025, Ballotpedia followed 50 announcements from U.S.Senate members who announced they would not seek re-election. January had the highest number of members announcing they would not run for re-election at 12. All but one announcement happened during odd-numbered years. The fewest announcements took place in April, June, July, August, and December at one each—all during odd-numbered years.