Even if you are (yes, I know she died, I'm speaking hypothetically) Mother Theresa and leave with a 5 year notice, and wash the feet of your boss using your hair? You can still be made a 'never rehire'. This is all nonsense. What will happen will happen. And they will reference you when you leave anyway they see fit, truthful or not. The ethics about treating employees as humans, something to be valued, is long gone. Welcome to America.
That said, there's another interesting point to be made about the consolidation of medical centers, doctor offices, labs, and the like: As more people cannot afford health care, they are not able to pay their bills. In the past, this would mean a trip to the collection agency, and bad credit scores. Increasingly, it now means that since you are in default of your medical bills, you are facing fewer choices to obtain health care if you need it since the provider you have not paid may have merged into a group of other providers- therefore none of them will treat you (aside from emergency room care).