It is a regional competition between men's professional clubs from six countries: Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia, Serbia, and Slovenia.

Based on the results in the national championships and by taking into account which clubs have sent applications for participation in the ABA League Second Division, these teams will play in the inaugural season of the ABA League Second Division.

[1] Teams from Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia, Serbia, and Slovenia previously played similar second-tier competition called First B Federal League when they were part of SFR Yugoslavia.

On 12 March 2020, the ABA League Assembly temporarily suspended the 2019–20 season due to the COVID-19 pandemic.

[6] The following is a list of clubs that have played in the Second Division, at any time, since its formation in 2017, to the current season.