Is the F-16 cockpit pressurized?
Yes, the cockpit of the F-16 is pressurized. However, there are two types of cabin pressurization:


Isobaric Pressurisation: The system maintains a constant cabin pressure (usually between 2000 and 8000 ft) as the atmospheric pressure decreases. This is used in commercial aircraft.
Hypobaric Pressurisation: In such a system the pressurisation commences at a 
given altitude and cabin altitude is maintained at this value until a preset pressure differential is reached. With continued ascent the pressure
differential is maintained. This is used in military aircraft including the F-16, as the weight penalty of the Isobaric system would seriously affect the range. 


Provision of supplemental oxygen in the aircraft ensures that the occupant receives increasing quantity of oxygen in the inspired air. The aircraft oxygen system (regulator assembly) ensures that the correct percentage of oxygen is added from the on-board Oxygen reserve to the inspired air in order to maintain lung pO₂ at 103 mm Hg.