The tremendous scaling of the semiconductor devices is producing the high-density integrated circuits (ICs). Metal-oxide-semiconductor field-effect transistors (MOSFETs) are the basic building blocks for the ICs. The lower area requirement with increased numbers of devices on a substrate makes it an interesting field of very-large-scale integration (VLSI) design. The reliability of the logic circuits is the concern issue in modern-era electronics. Reliability affects the overall performance of the logic circuits and possibility to the failure of the semiconductor devices. Negative bias temperature instability (NBTI) degradation is the major concern in ultra-deep submicron (DSM) regime. The negative threshold voltage of PMOS device when shifted in NBTI effect causes performance degradation over the time. NBTI degradation is the aging effect for PMOS device. This chapter presents the overview of NBTI effect and its possible solution.