Netflix removed “Phineas And Ferb” from its library on May 2nd. Neither Amazon Prime or Hulu currently carry the program, meaning the show’s not so easy to watch now. You either have to purchase the episodes and/or have a season pass, or find it on a VOD service. Please help me, where can I watch it?
Companies like this often only have a contract to carry a TV show for a certain amount of time, just like how a movie will first premiere on HBO, then later move over to Showtime, Cinemax or another channel.
Disney's also a little different in they still have the attitude that they put TV shows and movies in their "vault" so that when they re-release them about five or ten years later, they will "be fresh for new generations of young children". It's a holdover from when there was a lot more control over how and when people could watch something. You really didn't know when something was going to be in re-runs, or you had to buy the VHS tape or DVD before it wasn't available any more.
Now, we've got other options: DVRs, on demand video, iTunes/Amazon/Hulu/Netflix, etc., where the person makes the decision about when they'll watch something.
So, all I can say is either get the episodes on iTunes or else wait until Disney signs another contract with a streaming company to put the episodes back online.