An intravenous catheter assembly. The intravenous catheter assembly including a catheter and a catheter hub having a catheter hub body, a septum, and a septum retainer, the catheter hub body having an internal wall defining a transition step, wherein the septum positioned such that a first end of the septum abuts up against the transition step, the septum retainer at least partially insertable within the catheter hub body and configured to secure the septum in position.
