Disclosed embodiments of introducer devices provide hemostatic sealing and allow a delivery catheter to be inserted through the introducer seals without the use of a separate loader device that covers a medical device that is mounted on the catheter. Some disclosed introducers comprise a housing, a distal sheath extending distally from the housing and adapted to be inserted into a patient's vasculature, a distal hemostatic seal mounted within the housing and a proximal hemostatic seal mounted within the housing, and a slidable tube positioned within the housing that is movable longitudinally relative to the distal hemostatic seal between a proximal position and a distal position, wherein in the proximal position a distal end of the tube is positioned proximal to the distal hemostatic seal with the distal hemostatic seal closed, and wherein in the distal position the distal end of the tube extends through the distal hemostatic seal.