The Hannah Montana star, 15, begins the extended leg of the tour in Detroit on Jan. 11 and will wrap in Miami on Jan. 31. Tickets for the new gigs go on sale beginning this Saturday.
Disney said the concerts were added after an "overwhelming response" from fans, many of whom have missed Cyrus on her current 55-date tour – tickets for which sold out in minutes.
The Jonas Brothers, currently opening for Cyrus, will not appear at the added concerts. Aly & AJ will support Cyrus from Jan. 11 through Jan. 24. Another special guest will be announced for the final six dates from Jan. 25-31.
"Best of Both Worlds" has been among the top-selling tours of the year. Ticket sales earlier this fall were so brisk that observers compared Cyrus to the Beatles.
JOSH & FERGIE: ROCKED BY SCANDAL
Did he cheat with a stripper?
Married less than a year, the couple denies an Atlanta woman’s claims that she and Josh had a fling
Note that this week’s cover of PEOPLE may differ regionally
