The structure was also ratified two days ago by the Professional Cycling Council - a body comprising team, rider and race organiser representatives.
Three divisions will make up the new UCI Road International Calendar: the UCI WorldTour, UCI ProSeries and UCI Continental Circuits.
From 2020, the WorldTour calendar will include the three grand tours, the "other" stage races and the one day classic races - which will also be grouped under a new UCI "Classics Series" - for a total of around 185 days racing.
The 18 WorldTour teams - made up of 27-30 riders - will be required to race these WorldTour events, and the Classics Series which will include the five monuments (Milan-San Remo, Paris-Roubaix, Tour of Flanders, Liege-Bastogne-Liege, Il Lombardia) and up to 15 other events - all yet to be decided.
A new UCI ProSeries, will also be launched in 2020, comprising a mix of current HC and Class 1 events, as well as the UCI Continental Circuits.
Next year, the WorldTour ranking will no longer exist, replaced by a global, individual UCI World Ranking plus a World Ranking for nations and trade teams.
“I am very happy that all together, we have reached a favourable consensus for all stakeholders of men’s professional road cycling: teams, riders, organisers, sponsors and fans alike," UCI president David Lappartient said. "We now have a solid basis for continuing the development of our sport so that it becomes one of the major professional sports in the world, THE sport of the 21st century."
While hailed as new, the structure does not appear too dissimilar to what currently exists, but the UCI says more detailed information will be released soon.