As of March 16, 2,712 major party candidates have filed to run for the Senate and House of Representatives in 2020.

So far, 385 candidates are filed with the Federal Election Commission (FEC) to run for U.S. Senate in 2020. Of those, 322—168 Democrats and 154 Republicans—are from one of the two major political parties. In 2018, 527 candidates filed with the FEC to run for U.S. Senate, including 137 Democrats and 240 Republicans.

For U.S. House, 2,650 candidates have filed with the FEC to run in 2020. Of those, 2,390—1,121 Democrats and 1,269 Republicans—are from one of the two major political parties. In 2018, 3,244 candidates filed with the FEC, including 1,566 Democrats and 1,155 Republicans.

Thirty-six members of the U.S. House are not seeking re-election in 2020. That includes 27 Republicans and nine Democrats. Four senators (three Republicans and one Democrat) are not running for re-election. In 2018, 55 total members of Congress—18 Democrats and 37 Republicans—did not seek re-election.

On November 3, 2020, 35 Senate seats and all 435 House seats are up for election. Of those Senate seats, 33 are regularly scheduled elections, while the other two are special elections in Arizona and Georgia. Twelve are Democratic-held seats and 23 are Republican-held seats. In the House, Democrats currently hold a majority with 232 seats.

Additional Reading
United States Senate elections, 2020
United States House of Representatives elections, 2020
List of U.S. Congress incumbents who are not running for re-election in 2020