The Nationals acquired Mead from the White Sox on Saturday in exchange for catcher Boston Smith.
After being designated for assignment by the White Sox on Wednesday, Mead will regain a spot on the 40-man roster in a new organization. The 25-year-old infielder has slashed just .238/.300/.317 across 445 plate appearances in his MLB career, but he posted a .908 OPS at the Triple-A level last season and isn't far removed from a being a top prospect in the Rays system. Mead has no minor-league options remaining, so Washington will need to open up room for him on its 26-man active roster.