What education level comes after ivy league?

There's no education level that *comes after* Ivy League schools. "Ivy League" refers to a group of eight prestigious universities. Graduating from an Ivy League school is the end of an undergraduate or graduate degree program, after which one might pursue further education like a professional degree (law, medicine, etc.) or a postgraduate degree (PhD, etc.) at any university, including (but not limited to) Ivy League schools.