Same here. Had the misfortune of having to use US medical care once as well. First class service. Zero waiting time. Course before they did anything, they asked for my credit card & slapped several thousand dollars deposit charge on it. I knew I was covered from work (travel insurance), I didn't worry too much (I'd get reinbursed for any charges put on the credit card later).
And no, you won't be turfed onto the streets if you couldn't pay. You'd get just re-directed to one of the noticeably lower tier hospitals in the city (to my knowledge). I'm guessing, they'd be on a level significantly worse than any hospital here in Canada. Here's a tip: if travel restrictions ever get lifted *DO NOT EVER* travel outside the country without adequate travel insurance. If in doubt, get supplemental insurance - just in case. VERY easy to accumulate charges in the several thousands of dollars (my ambulance ride alone cost me just under two grand (US$)!).