Johnson became a member of the U.S. senior team in 2007. She had one of the best rookie seasons ever recorded in the history of gymnastics, winning the all-around at the American Cup, Pan American Games, U.S. National Championships, and World Championships all in her first year as a senior gymnast. She is the 2007 individual all-around World Champion, 2007 World Champion on floor exercise, and a member of the 2007 gold medal-winning U.S. gymnastics team. As well as being the 2007 U.S. Champion on balance beam and floor exercise, the 2008 U.S. Champion on floor exercise and silver medalist on balance beam, Johnson is a three-time U.S. all-around Champion, winning once as a junior and twice as a senior.