Recently, small-signal microwave performance has been reported for PNP InAlAs/InGaAs HBTs [1, 2]. While power performance of PNP AlGaAs/GaAs HBTs has been demonstrated [3], nothing has been reported on power performance of PNP HBTs in the InP material system. In this work, InAlAs/InGaAs PNP HBTs were fabricated and subsequently characterized under large signal conditions at X-band to determine their suitability for high-frequency power applications. PNP HBTs demonstrated fT and fmax as high as 13 and 35 GHz, respectively. Power performance at 10 GHz was comparable to InP-based NPN single HBTs, providing up to 10 dB of gain, 0.49 mW/μm2 of output power, and 24% power-added efficiency. Analysis of these HBTs suggests further design and epilayer optimizations for increased power performance.