User blog comment:Dragonknight86/Phineas and Ferb on Hiatus after Season 4 ends/@comment-4241330-20140216215142

As much as I hate to admit it, the show has gotten stale. Well, summer can't last forever, folks.

Or...maybe this is it for the summer-themed series. If a possible Season 5 arrives, the series will shift over to the kids going to school (much like Ed Edd n Eddy).