A breakaway hemostasis hub for a catheter or introducer sheath includes a splittable or separable housing, a seal within the housing, an actuator partially slidably disposed within the housing, a pair of spring retainer members in the housing each adapted to receive at least one spring, and a pair of actuator retainer members adapted to retain the seal, the actuator, and the spring retainer members in the housing. The actuator is operable to assume a closed position and an open position and includes a dilator member configured to dilate the seal when the actuator is in the open position. The hub is splittable or separable into two generally symmetrical sub-assemblies to facilitate cutting the catheter for retraction from the patient's body without displacing its payload.