Subject: Medical Procedures in retirement

Not quite an investing topic but would people here recommend delaying non-critical surgeries until medicare has started? Or is it better to get it done before medicare starts?

I'm fortunate enough where I have federal health insurance that I will keep after medicare starts so that should cover most expenses.

What I don't know or understand is whether having both federal health insurance and medicare would limit choices of surgeons as opposed to not having medicare (i.e., does medicare limit my doctor choices)?

Thanks
Rich