We report on heterogeneously integrated V-band amplifier realized in four layer interconnect InP heterojunction bipolar transistor (HBT). The amplifier chiplet is integrated onto a passive InP carrier wafer with two layers of interconnect using heterogeneous integrated interconnects, which enable electrically short connection between two technologies. The heterogeneously integrated interconnect or transition has measured loss of ≤ 0.1 dB up to 30 GHz and ~0.4 dB at 90 GHz. Measured amplifier S-Parameters show almost no difference between before and after integration versions. Relatively flat output power between 11.5 and 12.5 dBm was demonstrated from 55 to 65 GHz. This is the first reported integration of V-band amplifier chiplets using heterogeneous integration, as well as lowest reported loss for heterogeneous interconnect transition.