How do I switch cancer centers when my insurance changes?

Hi, In January 2027. I have to switch health insurance. My current one will no longer be contract with Medicare. So that mean I have to look for a new insurance which I found one but it's not contract with my current cancer center. I have to have to find a new cancer center and start all over 👎🏻😡😥😢. I'm not happy and wish to stay with Memorial Sloan Kettering. Oh dear not sure what's going to happen but I'm sad, depressed,.