On March 28, 2013, FX announced that the show had been picked up for a tenth season. FX President John Landgraf stated that there may be more seasons after that: “Whether it goes beyond that depends on whether the people who created the show want to go and whether the audience still wants to watch. (Source)
If trends from the past few seasons continue, it would probably begin airing in the fall of 2014. Whether it would be 10 episodes like Season 8, or would go back to the 13 episodes of previous seasons, has yet to be determined.
on July 21, 2013 Glenn Howerton was quoted in an interview with Rolling Stone that Season 10 would be the last:
Well, you’re funny on Sunny so let’s talk about that. Are you really quitting after ten seasons?
"Yes. There’s a certain point where you wear out your welcome and we don’t want to do that. We want to leave them wanting more. We spend a lot of time trying to find new lines to cross. We’re not trying to offend people or gross them out, but we’re looking to surprise them. I think we’re proud of what we’ve done so far, so it’s time to stop. I’m sure there are already a few people who are like 'Jesus Christ is that show still on? Go away.' "
On July 23, 2013 Glenn Howerton stated the following on Twitter: "That was a misquote in Rolling Stone, y'all. We're signed on through 10 seasons, but may do more." "It's a great article in Rolling Stone. I just think he misunderstood when I said we're only signed thru 10. We still might sign on for more."