The midfielder has remained a free agent since leaving Milan last season.
He announced today: "I will stop here. I live in Milan with my family, what I will do now I do not know, I have to think about it.
"Atalanta-Milan of May 13 2018 will remain my last game as a professional."
Montolivo, 34, spent seven years with the Rossonero and earned over 65 caps with Italy.