MEMs microbeams consist of many thin material layers. This thin layered structure is very similar to that of laminated composite plates in which thin layers of fiber-reinforced plastic are stacked and cured. Both the MEMs layered structure and the composites layered structure will have layers with different mechanical properties. Researchers in composite materials have developed an approach, referred to as laminated plate theory, to solve mechanics problems in these layered structures. This approach can be extended to characterizing MEMs mechanical behavior. For example, laminated plate theory can be used to evaluate displacement of MEMs microbeams that are actuated by PZT. In this work, measured deflections for a 1000 μm long, 300 μm wide, 2.675 μm thick beam are compared to laminated plate theory predictions. The model accurately predicts the deflection as a function of voltage applied to the PZT. An application of laminated plate theory to prediction of residual stresses is also briefly discussed.