The 20th Amendment sets congressional terms to begin at noon on January 3 of each year. The 119th Congress took office at noon on January 3, 2025, following the November 2024 elections. Before the 20th Amendment''s ratification in 1933, newly elected members had to wait until March 4—four months after the election—to take their seats, creating long lame-duck periods where defeated incumbents still held power.
This delay led to two problems the 20th Amendment solved. First, outgoing members who had lost reelection continued making laws for months after voters rejected them. Second, newly elected members faced emergencies they could not address because they had not yet taken office. By moving the start date to January 3, the amendment shortened the lame-duck period to about two months and ensured the people''s most recently chosen representatives could act sooner. The amendment also specifies Congress must assemble at least once every year, beginning at noon on January 3 unless Congress by law sets a different day.