série a2 is competed by 20 teams in three separate phases. in phase one, the teams are split into two groups, playing each other twice in a home-and-home series. the bottom two from each group are relegated to série a3; the top four advance to phase two. phase two consists of the eight advancing teams organized into groups, repeating the home-and-home series within the group. the top two placed teams from each group are promoted to série a1; each top team advances to phase three, a single championship game to determine the tournament winner.