The four element reconfigurable MIMO antenna system includes four conducting PIFA elements disposed on a top surface of a rectangular dielectric substrate. For each PIFA, an F-head portion of the PIFA defines two arms extending to a long peripheral edge of the substrate. An F-tail portion of the PIFA extends from a short peripheral edge of the substrate. A first PIFA and a second PIFA are mirror images of each other, and a third PIFA and a fourth PIFA are mirror images of each other. A meander pattern of conducting material extends from a bottom region of the F-tail portion of the PIFAs. For each PIFA, PIN/varactor diode bias circuits are disposed on the substrate's top surface, connecting to and extending away from a unique location on the F-tail portion of the PIFA, thereby creating separate radiating branches of the PIFA to achieve reconfigurability.