Legally the ER can't turn you away if you can't pay, in the US.
What they can do - specifically relevant if you're a US citizen - is send you a bill and then after you don't pay it send it off to collection agencies, which then harms your credit rating for the next five or seven years (I believe various states have different laws on when these have to drop off your credit rating, it's usually either seven years or slightly less). This has improved a bit lately, with new credit scoring updates that considerably reduce the hit from medical bill collections on your credit. However it's obviously still a ridiculous situation.
Most non-private hospitals in the US have low income programs you can sign up for (eg if you go into the ER due to an emergency and run up a big bill), that eliminate most or all of your bills if you fall under a certain income level. That's subsidized by government funding programs. Typically though if you're at that low of an income level, you should just sign up for Medicaid anyway. Those programs are usually most valuable when someone in the eg 22-50% income bracket (the most vulnerable in the US insurance system, where you're above Medicaid and below typical good paying career or job status) is caught inbetween insurance / jobs for a number of months and gets hammered by an ER visit.
What they can do - specifically relevant if you're a US citizen - is send you a bill and then after you don't pay it send it off to collection agencies, which then harms your credit rating for the next five or seven years (I believe various states have different laws on when these have to drop off your credit rating, it's usually either seven years or slightly less). This has improved a bit lately, with new credit scoring updates that considerably reduce the hit from medical bill collections on your credit. However it's obviously still a ridiculous situation.
Most non-private hospitals in the US have low income programs you can sign up for (eg if you go into the ER due to an emergency and run up a big bill), that eliminate most or all of your bills if you fall under a certain income level. That's subsidized by government funding programs. Typically though if you're at that low of an income level, you should just sign up for Medicaid anyway. Those programs are usually most valuable when someone in the eg 22-50% income bracket (the most vulnerable in the US insurance system, where you're above Medicaid and below typical good paying career or job status) is caught inbetween insurance / jobs for a number of months and gets hammered by an ER visit.