Fortunately for you, your family was able to scrape up the money for an aeromedical flight to the US, and somehow they were able to produce some sort of proof of citizenship that enabled your entry into this country. So they checked you out of the Mexican hospital and brought you to the airport, where your journey to the US and our bountiful (and free!) healthcare system could proceed.
Of course in our hypothetical scenario you are uninsured, and your local family spent all of their money on your treatment in Mexico, maybe a few bribes, and your medical flight here. But those are only minor inconveniences, really, thanks to EMTALA. You don't need no stinking MOT (transfer approval), you don't need to have an accepting physician, you don't even need to bring any paperwork or X-rays from the other hospital. And you certainly don't need insurance coverage. No copay? No problemo.
All you need to do is show up. Any ER will do, and we're open 24 hours a day even on weekends. Just pick the nicest hospital you know of that is most convenient for you. Don't bother going to those busy, dirty, impersonal county facilities. You deserve the best! It's your right.
You might get (relatively) lucky and happen to have an incidental emergency medical condition that requires hospital admission in order to stabilize you. Honestly, that would make both of us lucky, because it would be pretty hard for someone like me to discharge someone like you who can't care for yourself and whose family has made no other arrangements for your care. But it's also pretty hard to admit someone like you solely to arrange long-term nursing home care and rehabilitation, even if you might need more procedures in the upcoming weeks. No matter how sad and unfortunate your situation may be, "social" admits to the "no-doc" admitting staff are usually about as welcome as a fart in an elevator. Particularly when they are unfunded midnight weekend language-barrier system-abusing complicated social admits of questionable medical necessity.
When patients like you get admitted, you tend to be challenging for the hospitalists to discharge too, so you end up receiving much more medical care than the emergency stabilization which is mandated by EMTALA. And that is both the beauty and the curse of that legislation.