The ICC has increased from 12 to 16 the number of teams participating in the World T20, beginning with the 2014 event.
Teams can now play three Twenty20 Internationals in addition to the stipulated 12 in the year of a World Twenty20, along with a corresponding reduction in the maximum number of permitted ODIs.
The World Cup, for 50-over cricket, will have 10 teams from 2019 onwards, with the 2015 event being the last World Cup open to 14 teams.
The Board also released the first outline for its plans for the World Test Championship, with three games between four teams scheduled for 2017 and 2021.
The ICC's Executive Board has also confirmed a constitutional amendment that will alter the role of its president and create a new post of a non-voting Board Chairman.
This will be the fourth time the ICC has made a change in its presidential format since reworking its constitution in 1996.