This is true for any patient though. If you are not on their insurance plan, the chances that they will darken your door are just this side of zero.
Once in a blue moon it happens, but 99.99% of the time, it doesn't. Any one who has been out for any length of time has lost patients to another doctor who is "on the plan." I've only been out 7 years but I've worked with and for enough doctors who have been practicing 30 years and the same thing happens to them. These are patients that they have seen since the patient was a little kid, and now they are seeing their children or even grandchildren. But not on the plan = patient not seeing you....
And for the 100th time...think about it. I only go to providers who are on my plan and I'm sure you all do too. WHy would you expect your patients to be any different?