In a staggered election, the seats of the senators who were first disputed in 1922 were up for election. The Philippines is divided into 12 senatorial districts, of which all districts save for the 12th district, has one of its seats up.
In an interleaved voting schedule, the positions of senators first debated in 1922 were available for selection. The Philippines is segmented into 12 senatorial areas, with every area except the 12th having a single position open.