Possible revisions to the seismic design provisions of the New Zealand concrete design code NZS 3101: 1982 for ductile reinforced concrete moment resisting frames are discussed. Topics include shear reinforcement for beam-column joint cores, anchorage of longitudinal reinforcement passing through beam-column joint cores, and transverse reinforcement in columns for confinement in potential plastic hinge regions of columns. The recommendations are based on recent experimental and theoretical studies of the simulated seismic response of beam-column joints and columns in ductile reinforced concrete frames. Rational models for the evaluation of behaviour are presented.