The motion passed unanimously at the board's meeting Wednesday morning at AHSAA headquarters in suburban Montgomery.
The biennial reclassification has significant impacts on several local teams. Athens High moves up the new Class 6A, while East Limestone stays in 5A, the eighth-largest school in that class.
Ardmore will move up from 4A to 5A, but West Limestone stays in 4A. Elkmont jumps from 3A to the sixth-smallest school in 4A.
Tanner stays in 2A, now in the top fourth of that class. James Clemens in Madison, in its 3rd year, suddenly finds itself as the smallest school in the new Class 7A.
AHSAA Executive Director Steve Savarese will hold a press conference later Wednesday afternoon to discuss the new classifications.