A line chart showing the average age per Congress since 1901, with one line showing the average representative age and another line showing the average senator age. Both lines follow similar patterns, though the average senator age is 5 to 10 years older than the average representative age. Each line holds relatively steady from 1901 to 1981. In the years from 1981 to 2023, the lines each start climbing to their peak, which they are currently near.
Notes: The age of the membership is measured as of the first day of the first session of each Congress. Eight representatives of the 118th Congress who did not have birthday information immediately available were not included.
Graphic: Joe Murphy / NBC News