The kinetic structure and stability of subfast intermediate shocks (IS) are investigated using a hybrid code. The shocks are formed dynamically by the interaction between a flowing plasma and a stationary piston. For &thgr;BN=60¿ and plasma &bgr;=0.46, the strong IS is found to be stable with a width in the range of 10 to 20 ion inertial lengths (&lgr;i). The rotation of the transverse component of the magnetic field is in the ion sense. The weak IS has a more complex structure and consists of both Alfv¿n and slow waves. The leading edge of the shock is dominated by the Alfv¿n mode and is associated with a S-shape electron sense field rotation with a small decrease (increase) in the magnetic field (density) across it. Some of the ion dissipation occurs within this layer, which is relatively thin (~17--20 &lgr;i). However, the transition to the downstream density and magnetic field occurs in the much wider (~150 &lgr;i) trailing slow wave. The main heating associated with this trailing edge occurs in the direction parallel to the magnetic field. This slow wave has a phase velocity larger than the Alfv¿n speed due to kinetic corrections to linear wave properties. As a result, the slow wave stays attached to the leading edge of the shock which remains time-stationary. The classification of IS's, based on phase velocity of MHD modes, becomes ambiguous in the kinetic limit. When the magnetic field is noncoplanar, the strong IS becomes time-dependent and expands self-similarly in time, whereas the weak IS disintegrates into an RD. ¿ American Geophysical Union 1992