An expandable introducer assembly includes a dilator subassembly extending from a proximal end to a distal end. The dilator subassembly includes a dilator having an insertion portion disposed adjacent the distal end, an expansion portion disposed adjacent the distal end, and a tapered transition portion disposed between the insertion and expansion portions. The dilator subassembly includes a distal sheath disposed in overlaying relationship with the insertion portion of the dilator. An introducer subassembly is disposed in coaxial relationship with the expansion portion of the dilator, and includes a valve disposed adjacent the proximal end and an introducer sheath extending from the valve in overlaying relationship with the expansion portion of the dilator. An expandable sheath subassembly is releasably interlocked with the dilator subassembly and includes an expandable sheath disposed in overlaying relationship with the tapered transition portion and in nested relationship between the insertion portion and the distal sheath.