A compressor assembly having a piston with multiple cross sections. The compressor assembly, in one form thereof, includes a cylinder block defining a cavity. A piston is at least partially disposed in the cavity and reciprocates along a central axis of the cavity. The piston includes a first piston portion and a second piston portion. The first piston portion has a cross sectional configuration and area substantially similar to a first portion of the cavity and the second piston portion has a radially outer surface at least partially engageable with the sidewall of a second portion of the cavity. The second piston portion may also have a larger cross sectional area than the first portion of the piston which may be used to compress a refrigerant within the cavity.