A catheter hub assembly , comprising: a catheter hub body having a catheter hub body distal end operably coupled to a catheter tube , a catheter hub body proximal end , and a catheter hub body internal wall defining an internal fluid passageway therebetween, the catheter hub body internal wall defining a transitional step within the internal fluid passageway between a smaller diameter portion proximal to the distal end and a larger diameter portion proximal to the proximal end ; a septum having a septum distal end and a septum proximal end , wherein the septum is positioned within the internal fluid passageway such that the septum distal end abuts up against the transitional step ; and a septum retainer at least partially receivable within the internal fluid passageway of the catheter hub body , the septum retainer having a septum retainer outer wall and a septum retainer inner wall , wherein: (a) the septum retainer outer wall is shaped and sized to interlock with the catheter hub body internal wall and includes one or more septum retainer lateral ribs configured to inhibit rotation of the septum retainer relative to the catheter hub body ; (b) the septum retainer inner wall is shaped and sized to selectively couple the catheter hub assembly to a catheter insertion device and includes one or more lateral nubs configured to inhibit rotation of the septum retainer relative to the catheter insertion device; and (c) the frictional resistance provided by the one or more lateral ribs exceeds the frictional resistance provided by the one or more lateral nubs . a catheter hub body having a catheter hub body distal end operably coupled to a catheter tube , a catheter hub body proximal end , and a catheter hub body internal wall defining an internal fluid passageway therebetween, the catheter hub body internal wall defining a transitional step within the internal fluid passageway between a smaller diameter portion proximal to the distal end and a larger diameter portion proximal to the proximal end ; a septum having a septum distal end and a septum proximal end , wherein the septum is positioned within the internal fluid passageway such that the septum distal end abuts up against the transitional step ; and a septum retainer at least partially receivable within the internal fluid passageway of the catheter hub body , the septum retainer having a septum retainer outer wall and a septum retainer inner wall , wherein: (a) the septum retainer outer wall is shaped and sized to interlock with the catheter hub body internal wall and includes one or more septum retainer lateral ribs configured to inhibit rotation of the septum retainer relative to the catheter hub body ; (b) the septum retainer inner wall is shaped and sized to selectively couple the catheter hub assembly to a catheter insertion device and includes one or more lateral nubs configured to inhibit rotation of the septum retainer relative to the catheter insertion device; and (c) the frictional resistance provided by the one or more lateral ribs exceeds the frictional resistance provided by the one or more lateral nubs . (a) the septum retainer outer wall is shaped and sized to interlock with the catheter hub body internal wall and includes one or more septum retainer lateral ribs configured to inhibit rotation of the septum retainer relative to the catheter hub body ; (b) the septum retainer inner wall is shaped and sized to selectively couple the catheter hub assembly to a catheter insertion device and includes one or more lateral nubs configured to inhibit rotation of the septum retainer relative to the catheter insertion device; and (c) the frictional resistance provided by the one or more lateral ribs exceeds the frictional resistance provided by the one or more lateral nubs . <EOS>