This past spring (as of May 1, 2017), the AICPA updated their Service Organization Controls testing standards from the SSAE-16 to SSAE-18.
The following video from our friend Dan Hadaway, over at Infotex is a 5-minute overview of the changes and what to look for in the new reporting documents.
https://www.youtube.com/watch?v=gNAqsYOiNVg&feature=youtu.be