[joe5150]

That's not always the case. Some hospitals will still keep a record of the unpaid bill on your account even after they pass the debt to a collector, and the collector will report whether you pay to the hospital.

The practice and billing parts of the system are usually mostly separate, so the person checking you in for your appointments may not know or have any way to see that you have unpaid bills and you won't necessarily be denied care for it, but there's no real standard here either.