A catheter connector system, including a catheter hub and a coupling member. The catheter hub includes a cannula portion connected to a housing portion and a distal interface including a tapered seal post fixed to the housing portion, a deformable sealing element surrounding the tapered seal post, and a retention collar surrounding the sealing element. The coupling member includes an opening to receive the distal interface, an inwardly extending portion to engage the retention collar, and an actuating member to engage the deformable sealing element.