Powered drivers (10) for inserting an intraosseous device (160) into a bone and associated bone marrow are disclosed. Some of the powered drivers (10) may include a housing (12) having a distal end (14) and a proximal end (16)； a motor (18) disposed in the housing (12)； a driveshaft (34) extending outward from the distal end (14) of the housing in a direction away from the proximal end (16)； a gearbox (32) coupled to the motor (18) and to the driveshaft (34) such that activation of the motor (18) causes the driveshaft (34) to rotate； and a power source (40) configured to power the motor (18). A guard member (50) may be pivotably connected to the housing (12) and movable between a protective position and a non-protective position. The guard member (50) may be configured to cover the intraosseous (10) needle assembly in the protective position and to expose the intraosseous (10) needle assembly in the non-protective position. A biasing member (70) may be configured to urge the guard member (50) toward the non-protective position.
