Amplifiers with improved isolation are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit, etc.) includes an amplifier having a gain transistor, first and second cascode transistors, and a shunt transistor. The gain transistor receives an input signal and provides an amplified signal. The first cascode transistor is coupled between the gain transistor and an intermediate node and receives the amplified signal. The second cascode transistor is coupled between the intermediate node and an output node and provides an output signal. The shunt transistor is coupled between the intermediate node and circuit ground. The first and second cascode transistors are enabled to provide the output signal.; The shunt transistor is (i) disabled when the cascode transistors are enabled and (ii) enabled to short the intermediate node to circuit ground when the cascode transistors are disabled.