On August 15 the group released its fourth album, 1830m, and on August 24 (the first day of its Tokyo Dome concert series) AKB48 announced a reorganization of its teams.
Team 4 was dissolved, with its members transferred to the other three teams.
AKB48 has a system that allows members to "graduate" from the group when they are older and are replaced by trainees who are promoted.
Monica Hesse of The Washington Post described the AKB48 audition process as "rolling American Idol-esque".
On June 7, AKB48 and its related groups announced the results of the annual election to determine the lineup for its 37th single.
The winner was Mayu Watanabe with 159,854 votes, and Rino Sashihara was runner-up with 141,954 votes.
In January 2013 AKB48 played its Request Hour Set List Best 100 concert at Tokyo Dome City Hall, announcing future shows at Nippon Budokan On December 11 the group released its 34th single, "Suzukake no Ki no Michi de 'Kimi no Hohoemi o Yume ni Miru' to Itte Shimattara Bokutachi no Kankei wa Dō Kawatte Shimau no ka, Bokunari ni Nan-nichi ka Kangaeta Ue de no Yaya Kihazukashii Ketsuron no Yō na Mono", On February 24, during the group's Grand Reformation Festival event at Zepp Diver City Tokyo, the group announced a team reorganization.
This included a captain and co-captain of each team, promotion of AKB48 trainees to regular membership (with assignment to the four teams) and the transfer of members between AKB48 and its sister groups.
Aika Ōta was transferred to HKT48, Aki Takajō and Haruka Nakagawa to Jakarta-based JKT48 and Sae Miyazawa and Mariya Suzuki to SNH48.
The AKB0048 anime series was renewed for a second season, AKB0048 Next Stage, and aired from January 5 to March 30, 2013.
One of its concert venues, the Yokohama Arena, was used for a two-day charity event beginning on March 26 and 12 AKB48 members attended the Okinawa International Movie Festival that day for the same purpose.
On March 15, AKB48 announced that ¥500 million would be donated by the group, its sister groups SKE48, SDN48 and NMB48 and associates of AKS, its management company.
The top eighty candidates were ranked in five groups of sixteen.