Members of the House of Representatives serve two-year terms and are considered for reelection every even year. Senators however, serve six-year terms and elections to the Senate are staggered over even years so that only about 1/3 of the Senate is up for reelection during any election.
Accordingly, what elections are in 2018?
The 2018 United States elections will mostly be held on Tuesday, November 6, 2018. These midterm elections will take place in the middle of Republican President Donald Trump's term. All 435 seats in the United States House of Representatives and 35 of the 100 seats in the United States Senate will be contested.
How do congressional elections take place?
Congressional elections are held every two years. There are elections for 1/3rd of the Senate (who sit for six years) and for all of the House of Representatives who all stand for re-election after two years. These are held mid-way (two years) through a president's term in office and are called mid-term elections.