The Daily SuperHeros reports that Marvel has scheduled reshoots for the Captain America sequel in December and January. According to him, crews will gather up for two days of reshoots on December 16 and 17, then for approximately two weeks of reshoots in January.
No details were provided on what will be filmed. Most recently, Iron Man 3 went back for reshoots and Thor: The Dark World's reshoots added more Loki into the film's plot. Take this with a pinch of salt until officially announced.
Captain America: The Winter Soldier releases in theaters on April 4, 2014.