The electric field amplitude (E o) dependent dynamic ferroelectric hysteresis and polarization current density curves measured at room temperature for Na0.5Bi0.5TiO3 (NBT), showed three different stages of polarization reversal mechanism. The scaling relationship confirmed the dominance of domain wall motion at Stage I (i.e. upto E o < 35 kV cm-1), followed by domain switching at Stage II (35 kV cm-1 < E o < 60 kV cm-1). Interestingly, a unique behaviour with two sub stages was observed in Stage III (60 kV cm-1 < E o < 90 kV cm-1), with two distinct switching mechanisms viz., polarization rotation at Stage III-A and polarization extension at Stage III-B. X-ray diffraction analysis based on the Rietveld refined atomic positional co-ordinates, in electrically poled system strongly favors the polarization extension mechanism proposed at Stage III-B. The measured E o-dependent longitudinal piezoelectric response (d 33 and g33) values match closely with our proposed polarization reversal mechanism. © 2017 IOP Publishing Ltd.