On the heels of NBC picking up A.P. Bio, which is to star Glenn Howerton, Howerton and Kaitlin Olson have both confirmed that the thirteenth season of It's Always Sunny in Philadelphia is being pushed back to 2019. In Olson's own words: "We ended up pushing our next season a year because we were all busy with separate projects this year."
Currently, the gang is contracted to do at least two more seasons of the series, which means that Always Sunny is now likely to continue to air through 2020.