It is contested between thirteen professional clubs and operates on a promotion and relegation system with K League 1.

In 2011, the original K League announced a plan to begin a promotion and relegation system between the K League and a proposed second division.

[1] The K League then took steps to create the new second division, mainly with the addition of a split-system during the 2012 K-League season in which the bottom clubs are placed in a competition for safety with the last placed club being relegated to the new second division (originally it was going to be two clubs relegated but the withdrawal of Sangju Sangmu meant only one would be relegated).

In the case that teams are level on points, tie-breakers are applied in the following order: The K League 2 champions gain automatic promotion to K League 1.

The fourth and fifth-placed teams in K League 2 play against each other in the first round of the K League 2 play-offs, with the winner facing the third-placed team in the second round.