Kilgore will be available following the team's game against the Baltimore Ravens and prior to their matchup against the division rival Seattle Sehawks.
Kilgore was the starter last season and played well for the 49ers before suffering a fractured left leg during week 7. He had a follow-up surgery in June and started training camp on the PUP list.
Because he did not practice with the team during training camp, he was eligible to start the season on the PUP list.
The move counts as a roster exemption as the team makes moves to get the roster down to 75 players from 89.