These House races could determine which party is in control in the next Congress

All 435 seats in the House of Representatives are on the ballot when voters head to the polls on Nov. 3. But spread across the political map, there are 16 races that ABC News rates as tossup in which the outcomes are expected to come down to the wire and will be crucial to determining the balance of power in the House for the 120th Congress.

Democrats must net at least a three-seat gain to take control.

Here are the races that ABC News rates as Tossup:

Florida 14: Incumbent Democrat Kathy Castor vs. Republican Mike Beltran

Castor, a 10-term incumbent, is facing off against Trump-endorsed former trial lawyer Beltran. The seat became more competitive after Florida’s legislature redrew this district, putting Castor on the defensive.

Florida 22: Open -- Democrat Pia Dandiya vs. Republican Casey Askar

The battle for Florida’s newly drawn district spanning parts of Palm Beach and Broward counties and the city of Naples puts two political newcomers in the ring: Marine Corps veteran Askar against former teacher and U.S. Education Department official Dandiya.

Iowa 2: Open: Democrat Lindsey James vs. Republican Joe Mitchell

As incumbent congresswoman Ashley Hinson runs for Senate, this historically red House seat in the Hawkeye State is now up for grabs. James, a state representative and chaplain, is running against Mitchell, a 29-year-old lobbyist and former state representative who worked on Trump’s transition team. Trump won this district by 10 points in 2024, but the economic impacts from the Iran war and tariffs on this agriculture-heavy district have made this race competitive.

Kentucky 6: Open -- Republican Zach Dembo vs. Democrat Ralph Alvarado

GOP Rep. Andy Barr’s bid to fill Mitch McConnell’s long-held Senate seat leaves his Kentucky House seat open. Dembo, a former federal prosecutor and Navy JAG officer, faces Alvarado, a physician and former state senator. This district used to be more competitive, but redistricting in 2022 has made it friendlier to Republicans in recent years – though Barr was a consistent Democratic target since he was elected in 2012.

Michigan 4: Incumbent Republican Bill Huizenga vs. Democrat Sean McCann

Huizenga, who has served in Congress since 2011, is being challenged by McCann, a state senator. Huizenga does have incumbency advantage and outperformed Trump substantively in 2024, but his race appears to be tightening as many pollsters anticipate a sour political environment for the president’s party.

Michigan 7: Incumbent Republican Tom Barrett vs. Democrat William Lawrence

First-term congressman and former Army helicopter pilot Barrett, who has repeatedly bucked Trump by voting to limit his war powers in Iran, hopes to keep his seat and defeat progressive candidate Lawrence, a co-founder of the progressive Sunrise Movement. Despite the split, Trump has campaigned in favor of Barrett’s reelection in the competitive swing district, where Democrat Elissa Slotkin beat a Republican in 2018 to flip this seat before she ultimately won a bid for Senate in 2024.

Michigan 10: Open -- Democrat Christina Hines vs. Republican Mike Bouchard

As Rep. John James runs to be Michigan’s next governor, his open seat in North Detroit is up for grabs. The battle is between Hines, a former prosecutor, and Bouchard, an Army veteran. Trump carried this district by more than six points in 2024.

Montana 1: Open -- Democrat Sam Forstag vs. Republican Aaron Flint

Rep. Ryan Zinke’s retirement has left this Montana seat open with no incumbency advantage for Republicans. Flint, an Army veteran and conservative radio show host, is running against Forstag, a union leader and wildland firefighter smokejumper. Trump won this district covering western Montana by nearly 12 points in 2024.

North Carolina 1: Incumbent Democrat Don Davis vs. Republican Laurie Buckhout

In North Carolina, Davis, an Air Force veteran, is in a tough rematch against Trump-endorsed Buckhout, a retired Army colonel who served in Iraq. This district, which was redrawn, is a top target for Republicans and Davis is mentioned as the most-endangered Democratic incumbent despite the favorable nationwide political forecast for his party.

New York 17: Incumbent Republican Mike Lawler vs. Democrat Cait Conley

Lawler is one of two Republicans running for reelection in Kamala Harris-won districts this cycle – six others opted against another term in the House. Lawler has kept this seat in a blue state since 2022, outperforming Trump in 2024 by 2.8%. Lawler, who secured State and Local Tax (SALT) deductions during the Trump tax bill negotiations, is running against Conley, an Army combat veteran.

Ohio 7: Incumbent Republican Max Miller vs. Democrat Brian Poindexter

Miller’s reelection bid has been hampered by allegations of domestic assault against his ex-wife Emily Moreno, the daughter of Ohio Republican Sen. Bernie Moreno. Miller, a former Trump aide, has flatly denied wrongdoing and has not been charged with any crimes and refused to drop out of the race despite widespread calls from Republicans. Trump stopped short of calling on Miller to withdraw last summer, calling the situation "sad.” He’s being challenged by Poindexter, a union organizer and ironworker.

Ohio 9: Incumbent Democrat Marcy Kaptur vs. Republican Derek Merrin

The longest-serving woman in congressional history, Kaptur wants to keep her seat in this Toledo-area district for a 23rd term. She’s facing Merrin, a real estate investor and former state representative. Kaptur narrowly defeated Merrin in 2024, even as Trump won the district by 6.5 points. Redistricting has shifted the district more to the right, but Kaptur could be aided by Democrat interest in the Buckeye State’s Senate race.

Pennsylvania 8: Incumbent Republican Rob Bresnahan vs. Democrat Paige Cognetti

Trump-backed Bresnahan, who represents Scranton and Wilkes-Barre, is seeking reelection against Cognetti, the mayor of Scranton. Bresnahan helped Republicans gain control of the House by flipping this seat in 2024.

Texas 15: Democrat Bobby Pulido vs. incumbent Republican Monica De La Cruz

De La Cruz, who was first elected in 2022, is seeking to keep her seat in a South Texas district that is nearly 80% Latino. Redistricting expanded the 15th into Hidalgo County and shifted some of her GOP voters into neighboring districts. Pulido, a Latin Grammy-winning Tejano singer, is challenging De La Cruz in a race that could test Trump’s standing with Latino voters.

Texas 35: Open -- Democrat Johnny Garcia vs. Republican Carlos De La Cruz

This East San Antonio seat, previously held by Democratic Rep. Greg Casar, is open after the chair of the Democratic Progressive Caucus changed districts because of redistricting initiated by the Republican-controlled legislature. Garcia, a deputy sheriff, hopes to keep the district blue and is running against Trump-endorsed De La Cruz, an Air Force veteran and brother of Rep. Monica De La Cruz.

Virginia 1: Incumbent Republican Rob Wittman vs. Democrat Shannon Taylor

In North Virginia and the Middle Peninsula, 10-term Republican Wittman is battling to keep his seat against Taylor, Henrico County’s top prosecutor. It is one of a few districts across the country where Kamala Harris in 2024 outperformed Joe Biden in 2020, suggesting the district is trending left.