Ryan Murphy and Brad Falchuk's horror creation will be in the fold for a long time. FX confirmed American Horror Story season 8 and 9.

American Horror Story season 6 was a refresh for the franchise, a marked improvement over Freak Show and Hotel. It’s given FX the confidence to renew the series for American Horror Story Seasons 8 and 9.
John Landgraf, CEO of FX Networks and FX Productions, touted the landmark horror series in a statement.
“American Horror Story launched the modern limited series revolution and – as evidenced by the most recent installment ‘Roanoke’ - it remains as vital today as when Murder House stunned audiences six years ago,” said Landgraf. “Each new chapter is a cultural event, beloved for every new twist in imagery, style, cast and plot. We are thrilled that Ryan Murphy, Brad Falchuk and the entire creative team will continue to deliver the groundbreaking, celebrated American Horror Story for years to come.”
AHS is a winner in the key demo for FX. It's the No. 1 limited/mini series among adults 18-49, even though that term is a bit unfair for a series in its sixth season. Regardless of how you lump anthologies into ratings and awards categories, AHS is pulling in around 10 million linear and nonlinear viewers per episode. That’s enough to keep the series from creators Ryan Murphy and Brad Falchuk around for a long time.
American Horror Story season 7 will debut in the fall of 2017. We have more information on season seven here.