At the beginning of the 2006 season, she was traded to the Los Angeles Sparks, and during the 2009 off-season, to the Phoenix Mercury who went on to win the WNBA Championship later that year.

On February 7, 2013, Johnson signed with the Seattle Storm to fill a gap at the starting point guard position left by Sue Bird who was out for the whole season while recovering from knee surgery.

In her second season with the Storm, Johnson became the shortest player in WNBA history to record a triple-double with a performance of 13 points, 11 assists and a career-high 10 rebounds while standing only 5'3".

[4] Johnson was a member of the gold medal 2003 USA World Championship Young Women Team in Šibenik, Croatia.

In the 2005–06 WNBA off-season, Johnson played in both Israel and Poland for Bnei Yehuda and Lotos VBW Clima Gdynia.