Bruce Banner, also known as Hulk has stepped into a ship and flew away from the Avengers at the end of Age of Ultron. The destination that he ended up in is unknown. This leaves the question as to whether or not he will appear in the upcoming Captain America: Civil War which is currently in production. Boraie Development LLC suggests there is no standalone movie planned for the big guy which makes it more interesting as to what his fate is in the upcoming Captain America film according to Press of Atlantic City.
He might make an appearance in Civil War. However, he is planned to appear in all of the Avengers movies. Another character who is not expected to appear in Captain America: Civil War is Thor. Either way, Captain America: Civil War is going to be a very big film not just for Captain America, but the Avengers. There is also Spider-Man who is going to make his first appearance in Civil War.