(CNN) The battle for control of Congress is less than a year away and some House lawmakers are already deciding not to run for reelection, setting up a few potentially interesting campaigns in the 2020 election.

Along with 23 Republicans, six Democrats are retiring. Five Republicans and three Democrats are leaving to seek different offices, such as campaigning for a Senate seat or running for governor in their states.

GOP retirements

1. Rep. Rob Woodall of Georgia announced on February 7, 2019, he will retire at the end of the term.

2. Rep. Susan Brooks of Indiana , the recruitment chair for the National Republican Congressional Committee for the 2020 election cycle, announced on June 14, 2019, that she will not run for reelection.

3. Rep. Paul Mitchell of Michigan announced on July 24, 2019, in a House floor speech that he will not seek reelection.

4. Rep. Pete Olson of Texas announced on July 25, 2019, in a statement that he will not run for reelection in 2020.

5. Rep. Martha Roby of Alabama announced on July 26, 2019, that she will not seek reelection for a sixth congressional term in 2020.

6. Rep. Rob Bishop of Utah, the ranking member of the House Natural Resources Committee, confirmed to The Deseret News on July 29, 2019, that he won't seek reelection in 2020.

7. Rep. Mike Conaway of Texas , the ranking member of the House Agriculture Committee, announced on July 31, 2019, he will not run for reelection.

8. Rep. Will Hurd of Texas announced on August 1, 2019, on Twitter that he will not seek reelection and will "pursue opportunities outside the halls of Congress to solve problems at the nexus between technology and national security."

9. Rep. Kenny Marchant of Texas announced on August 5, 2019, that he will not run for reelection, writing in a statement "I am looking forward to finishing out my term and then returning to Texas to start a new chapter."

10. Rep. John Shimkus of Illinois announced on August 30, 2019, that he will not seek reelection in 2020. He has been in Congress since 1997.

11. Rep. Bill Flores of Texas announced on September 4, 2019, that he will not seek reelection in 2020. He first won his seat in Congress in 2010.

12. Rep. Jim Sensenbrenner of Wisconsin , the second-most-senior member of the House, announced on September 4, 2019, that he will retire in January 2021. He has been in Congress since 1978.

13. Rep. Mac Thornberry of Texas announced on September 30 that he will not seek reelection in 2020, making him at least the sixth Texas Republican lawmaker to do so this election cycle.

14. Rep. Francis Rooney of Florida announced on October 19 he will not seek reelection, after suggesting he was open to supporting the impeachment of President Donald Trump.

15. Rep. Greg Walden of Oregon , the top-ranking Republican on the House Energy and Commerce Committee, announced on October 28 he will not seek reelection.

16. Rep. Peter King of New York , a former chairman of the House Homeland Security committee, announced on November 11, 2019, that he will not seek releection in 2020. He has served in Congress since 1993.

17. Rep. Tom Graves of Georgia announced on December 5, 2019, he planned to leave Congress at the end his term to "join my family in their new and unique journeys."

18. Rep. George Holding of North Carolina announced on December 6, 2019, he won't seek reelection, saying in a statement that "newly redrawn congressional districts were part of the reason" for his decision.

19. Rep. Ted Yoho of Florida announced on December 10, 2019, he won't seek reelection, saying he will "pass the baton onto a new generation" and honoring his campaign promise not to serve more than four terms.

20 . Rep. Mark Walker of North Carolina announced on December 16, 2019, that he won't seek reelection, saying instead he will "take a look at the 2022 Senate race."

21. Rep. Mark Meadows of North Carolina said on December 19, 2019, that "after prayerful consideration and discussion with family," he won't run again in 2020, but added that his work "with President Trump and his administration is only beginning."

22. Rep. Phil Roe of Tennessee announced on January 3, 2020, that he will finish his term and retire at the end of the 116th Congress.

23. Rep. Ralph Abraham of Louisiana announced on February 26 that he will retire at the end of his term.

Democratic retirements

1. Rep. Jose Serrano of New York announced on March 25, 2019, that he has Parkinson's disease and will not run for reelection.

2. Rep. Dave Loebsack of Iowa announced on April 12, 2019, he will not run for reelection.

3. Rep. Susan Davis of California , the second-highest-ranking Democrat on the House Education and Labor Committee and the House Armed Services Committee, announced on September 4, 2019, that she will not seek reelection. She has been in Congress since 2001.

4. Rep. Nita Lowey of New York, the chairwoman of the influential House Appropriations Committee, announced on October 10, 2019, that she will not seek reelection after serving for more than three decades in Congress.

5. Rep. Pete Visclosky of Indiana announced on November 6, 2019, that he will not seek reelection in 2020. Visclosky chairs the House appropriations subcommittee on defense.

6. Rep. Denny Heck of Washington announced on December 4, 2019, that he will not seek reelection in 2020. Heck is a member of the House Intelligence Committee and he cited the committee's work on the impeachment inquiry into President Donald Trump as having " rendered my soul weary ."

Resignations - lawmakers leaving office before the end of their term

1. Republican Rep. Sean Duffy of Wisconsin announced on August 26, 2019, that he will resign in late September, saying in a statement that he wants to spend more time with his family ahead of the upcoming birth of his ninth child.

2. Republican Rep. Chris Collins of New York announced his resignation on September 30, 2019, ahead of his guilty plea to federal charges in an insider trading case.

3. Democratic Rep. Katie Hill of California announced her resignation from Congress on October 27, 2019, following her admission to an inappropriate relationship with a campaign staffer before she took office.

Seeking different office

1. Rep. Bradley Byrne, an Alabama Republican, announced on February 20, 2019, that he would run for Democratic Sen. Doug Jones' Senate seat in 2020.

2. Rep. Ben Ray Luján, a New Mexico Democrat, announced on April 1, 2019, that he would run to fill retiring Sen. Tom Udall's New Mexico Senate seat in 2020.

3. Rep. Greg Gianforte, a Montana Republican, announced on June 14, 2019, that he would run for governor of Montana.

4. Rep. Roger Marshall, a Kansas Republican, launched a bid for retiring Sen. Pat Roberts' Senate seat on September 7, 2019.

5. Rep. Paul Cook , a California Republican, announced on September 17, 2019, that he will leave the House in 2020 in order to seek a seat on San Bernardino County Board of Supervisors.

6. Rep. Joe Kennedy of Massachusetts launched a Democratic primary bid to challenge Sen. Ed Markey for his US Senate seat on September 21. Markey is up for reelection in 2020.

7. Rep. Tulsi Gabbard, a Hawaii Democrat, announced on October 25 she will not seek reelection for her congressional seat as she runs for the Democratic nomination for president in 2020.

8. Rep. Doug Collins, a Georgia Republican, announced on January 29 that he will run in the Republican primary for the US Senate seat currently held by fellow Republican Kelly Loeffler.

Deaths

1. Republican Rep. Walter Jones of North Carolina died on February 10, 2019.

2. Democratic Rep. Elijah Cummings of Maryland died on October 17, 2019.

This story has been updated with additional developments and will continue to be updated.