Now, it is known Keenum will need to determine where he fits with another team.
Denver will get a sixth-round pick and Washington will get a seventh-rounder plus Keenum, Rapoport added.
Washington needed another signal-caller given the uncertainty surrounding Alex Smith, who continues to rehabilitate from a gruesome leg injury suffered during the 2018 regular season.
Keenum is set to join his fifth team since entering the league as an undrafted free agent with the Houston Texans in 2012.
He signed a two-year deal with the Broncos last offseason, but Denver's pending trade for quarterback Joe Flacco made Keenum expendable. Before joining the Broncos in 2018, Keenum spent the 2017 season with the Minnesota Vikings, parts of the 2014 season with the Texans and Rams, and then with the Rams from 2015 to 2016.
On his career, Keenum holds a 26-28 record as a starter and has passed for 12,661 yards and 64 touchdowns with 42 interceptions.