Safety DeAngelo Hall, linebacker Houston Bates and wide receiver Kendal Thompson joined Reed on the PUP list. The players in the group are ineligible to practice until activated.
The Redskins did not designate a specific ailment for Reed, who did not participate in voluntary offseason workouts before making appearances in minicamp in June.
Reed recorded 66 receptions for 686 yards and six touchdowns in 12 games last season. The 27-year-old has missed time with a concussion and a shoulder injury.
Hall and Bates are recovering from knee surgery while Thompson is nursing an undisclosed injury.