UCare: what plans do providers need to be Medicare eligible?

Does anyone have a clear answer to what UCare plans we must bill with providers who are Medicare eligible? I have been told a couple of different answers by UCare reps. Curious if anyone else has asked this ? to them.

I have that the providers must be Medicare eligible for the following UCare plans: Essentiacare, UCare Connect Medicare (a rep told me this is a new plan, I know about UCare Connect, which is a SNBC plan and I think anyone can see these clients) and UCare for Seniors.