The most recent school to leave the FBS ranks is Idaho, which downgraded its program to FCS (the Football Championship Subdivision) after the 2017 season.
Notably, Idaho is the only program to voluntarily downgrade from FBS to FCS without extenuating circumstances since the NCAA created those subdivisions in 1978.
Two teams that met NCAA requirements to remain in I-A at that time, McNeese and Yale, chose to voluntarily downgrade to align with the rest of their conferences.
Most never returned to I-A/FBS, with the most significant exceptions being Cincinnati and most members of the Mid-American Conference, which were reinstated into I-A after only a single season at the I-AA level.
Schools that still compete in NCAA sports are listed with their current athletic brand names, which do not necessarily match those used by past members of FBS and its predecessors during their tenures at that level.