The All-Ireland Senior Football Championship will have two tiers from next summer.
Three quarters of delegates backed a Central Council motion at Congress to introduce the change for the next three seasons.
Teams in Division Three and Four of the League will play in the new 16 team second tier, unless they reach their provincial final.
A Tipperary motion was carried to determine that Tier Two standings will be determined at the end of the League rather than at the start.
Delegates have also backed the introduction of an advanced mark, sin bin and kick-outs from the 20-metre line in Gaelic football.
#GAA news: A two tier All Ireland Senior Football Championship format will be introduced in 2020!
— The GAA (@officialgaa) October 19, 2019