99 Seats in Congress Will Change Hands: What to Know

Ninety-nine seats in Congress — 83 in the House and 16 in the Senate — will have a different member than at the start of 2025, according to NPR reporting on Sept. 16, 2026.

The count covers three categories. Sixteen members across the House and Senate died or resigned during the 119th Congress, the current two-year session. Thirteen incumbents, meaning current officeholders running again, were defeated in primaries. Thirteen senators and 60 House members said they plan to retire or run for a different office in the 2026 cycle.

Six lawmakers died in office. They were Democratic Reps. Sylvester Turner of Texas, Raúl Grijalva of Arizona, Gerry Connolly of Virginia and David Scott of Georgia, Republican Rep. Doug LaMalfa of California, and Republican Sen. Lindsey Graham of South Carolina.

House departure records list added detail on vacancies. Rep. Marjorie Taylor Greene, R-Ga., resigned on Jan. 5, 2026. Rep. LaMalfa died on Jan. 6, 2026. Rep. Eric Swalwell, D-Calif., resigned from office during the 119th Congress.

Retirement announcements include some of the longest-serving members. California Rep. Nancy Pelosi and Kentucky Sen. Mitch McConnell said they will retire ahead of the midterms. McConnell said he will end a 40-year career in Congress. Sen. Jeanne Shaheen retired ahead of the 2026 midterms.

Other House departures were announced before primary season. Rep. Nydia M. Velázquez, D-N.Y., said she will not seek reelection in 2026. Rep. Bonnie Watson Coleman of New Jersey's 12th District said she will retire when her present term expires at the end of the 119th Congress. Rep. Don Bacon of Nebraska's 2nd District said he will not seek reelection in 2026 and will retire at the end of the 119th Congress.

The total grew through the summer. As of Aug. 13, 2025, 10 senators and 25 House members had said they did not plan to run for reelection ahead of the midterms. As of Sept. 15, 2026, 71 current House members — 30 Democrats and 41 Republicans — will not be back next term, according to AP tracking.

Runs for higher office account for a large share of the open seats. More than 30 members of Congress sought a different office in 2026, and just over half won their primaries. A primary is the party election that picks the nominee for November. Minnesota Sen. Amy Klobuchar and Tennessee Sen. Marsha Blackburn, whose Senate seats are not up in 2026, are presumptive favorites to become their states' governors, at which point they would resign from Congress.

Primary defeats added to the turnover. The 13 defeated incumbents in the final tally compare with earlier counts taken while primaries were still underway. An Aug. 24 tally listed 11 incumbents who had lost primaries and one who withdrew. By June 24, House incumbent primary defeats had reached seven, already above the postwar historical average, according to the University of Virginia Center for Politics. Louisiana's House primaries were delayed to Nov. 3, 2026 after congressional redistricting.

Alaska produced a same-name ballot pairing. Dan J. Sullivan advanced from Alaska's U.S. Senate primary in the 2026 midterms, according to AP. He goes by Dan Sullivan, the same name as the Republican incumbent.

Senate turnover sits within a fixed class structure. Class II is one of three Senate groups with terms that run from Jan. 3, 2021 to Jan. 3, 2027, ending with the 119th Congress. Democrats needed to flip four Senate seats to take control in the 2026 midterms.

The 2026 departures approach a modern precedent. The 1992 cycle saw 65 House members and nine senators not seek reelection, the only election in the last century with more retirements or runs for other offices than 2026, according to Brookings Institution's Vital Statistics on Congress.

The broader context here is institutional churn rather than any single race. A 99-seat turnover resets committee rosters, seniority ladders and campaign recruitment for the next Congress. For practitioners, the practical work is district by district: open-seat ratings, appointee succession where vacancies allow it, and the House and Senate freshmen who will set the margins for floor operations in 2027.