(unless there's been news since the article below I read from variety last year while season 4 was still airing)

"A 13-episode fifth season will air in 2017. The sixth and last season will consist of 10 episodes and air in 2018. "

http://variety.com/2016/tv/news/the-americans-renewed-last-two-seasons-fx-show-ends-1201782857/