There are guidelines that are in place in the psychology community that say to wait for two years. I get the impression there are a ton of those "unspoken" rules that almost all T's follow.

But other than having a sexual relationship with clients, there are no state laws that I am aware of.

I also know that my T has said I will be able to contact her after my therapy is done if I need her for something, but I get the impression it will never be a mutual relationship.