Will there be a familiars book 5 2015 2016?

As of my last knowledge update in October 2023, there has been no official announcement regarding a fifth book in the "Familiars" series by Adam Jay Epstein and Andrew Jacobson. The series originally concluded with "The Familiars: Circle of Heroes," which was released in 2013. For the most current information, it's best to check the authors' official websites or social media channels.