The impact of gate and drain leakage on V TH drift and dynamic-R ON of 100 V p-GaN gate AlGaN/GaN HEMTs is investigated in this work. Devices presenting two different AlGaN barrier layer designs are characterized by means of DC gate/drain leakage and Pulsed I-V measurements. Results show that a larger gate leakage yields a reduced positive V TH drift under off-state stress at large V DS , coherently with hole injection in the floating p-GaN gate. Conversely, a larger off-state drain leakage current exacerbates the R ON degradation at high V DS,stress due to hot-electrons effects. The application of a negative V GS,stress has been demonstrated to solve this issue, thanks to a more pinched-off channel that avoids hot-electrons related issues.