A delivery device for delivering an implantable leadless pacing device , the delivery device comprising: an outer tubular member including a lumen extending from a proximal end to a distal end thereof; an intermediate tubular member including a lumen extending from a proximal end to a distal end thereof, the intermediate tubular member slidably disposed within the lumen of the outer tubular member , the intermediate tubular member including a distal holding section defining a cavity therein for receiving an implantable leadless pacing device ; an inner tubular member including a lumen extending from a proximal end to a distal end thereof, the inner tubular member slidably disposed within the lumen of the intermediate tubular member ; a handle assembly including at least a first hub portion attached to a proximal end section of the outer tubular member , a second hub portion attached to a proximal end section of the intermediate tubular member , and a third hub portion attached to a proximal end section of the inner tubular member ; a longitudinally extending groove having a proximal end and a distal end disposed in an outer surface of the second hub portion , wherein the distal end of the groove is circumferentially offset from the proximal end of the groove ; and a multi-stage deployment mechanism disposed within the handle assembly ; wherein the multi-stage deployment mechanism is configured to incrementally deploy an implantable leadless pacing device ; wherein the multi-stage deployment mechanism includes an inwardly extending mating feature disposed in the third hub portion configured to be disposed within the groove . an outer tubular member including a lumen extending from a proximal end to a distal end thereof; an intermediate tubular member including a lumen extending from a proximal end to a distal end thereof, the intermediate tubular member slidably disposed within the lumen of the outer tubular member , the intermediate tubular member including a distal holding section defining a cavity therein for receiving an implantable leadless pacing device ; an inner tubular member including a lumen extending from a proximal end to a distal end thereof, the inner tubular member slidably disposed within the lumen of the intermediate tubular member ; a handle assembly including at least a first hub portion attached to a proximal end section of the outer tubular member , a second hub portion attached to a proximal end section of the intermediate tubular member , and a third hub portion attached to a proximal end section of the inner tubular member ; a longitudinally extending groove having a proximal end and a distal end disposed in an outer surface of the second hub portion , wherein the distal end of the groove is circumferentially offset from the proximal end of the groove ; and a multi-stage deployment mechanism disposed within the handle assembly ; wherein the multi-stage deployment mechanism is configured to incrementally deploy an implantable leadless pacing device ; wherein the multi-stage deployment mechanism includes an inwardly extending mating feature disposed in the third hub portion configured to be disposed within the groove . <EOS>