The 101st United States Congress began on January 3, 1989.
There were 11 new senators (five Democrats, six Republicans) and 31 new representatives (16 Democrats, 15 Republicans), as well as one new delegate (a Democrat) at the start of the first session.
Additionally, two senators (one Democrat, one Republican) and 12 representatives (nine Democrats, three Republicans) took office on various dates in order to fill vacancies during the 101st Congress before it ended on January 3, 1991.