In addition to the star atop the tree, there will be plenty of stars on the ground on “TNT’s Christmas in Washington” Dec. 20 primetime special.
 
Mary J. Blige, Neil Diamond, Sugarland, Rob Thomas, Usher and his protégé, 15-year-old Justin Bieber, are all slated to appear on the show, as well as President Barack Obama and First Lady Michelle Obama. The annual event, hosted by George Lopez, benefits the National Children’s Medical Center.

This marks TNT’s 11th presentation of the event, which is in its 28th year.