It is, but at the same time it isn't. The only reason I say it isn't is a financial concern.
If they do not have a credentialed admitting doctor at the external facility, there's really not a whole lot the ED(where the patient would need to be admitted through) can use as fact. So they have to do a whole lot of their own tests, which take more time. And then the resident/attending in the ED would need to make the call to send them up to a specialty unit to get the proper care they need. During this time, if it really is an emergency situation, the patient could die.
Why can't they just accept what the external hospital/care facility says without a doctor with attending privileges? There has to be a documented reason for admission from a credentialed physician with admitting rights in the medical record before the admission takes place. A physician may also have to have good reason to admit. Without any of that documented, insurance(obamacare, medicaid, or any other private insurance) can reject any and all charges sent to them.
Interesting. Keep in mind it defines local as within a certain amount of miles. So that clinic could have a doctor at a hospital just outside the range of that definition. I can see that being an issue in many scenarios. For example large metro areas like Houston or Los Angeles.