Can existence be predicated of individuals for Plato?

Aristotle famously argued that "being" is not a genus. This implies that , for him, "existence" cannot be logically predicated of individuals. But for Plato, "being" is a genus (one of the five "great" ones). Does this mean that, for him, existence can be (pace Russell) logically predicated of individuals (i.e., constitutes, as such, an essential determination)?