I need help on what to do about paying a hospital bill!?

Unforunately, your grandmother is not in a good position. Are you absolutely certain that her Mexican insurance will not cover any of her expenses? Some nations do cover their citizens abroad...that's why I ask. However, as someone else noted, she will not be eligible for any type of government/public assistance in the U.S. The hospital may be willing to work out an extended payment arrangement but the hospital bill will be a whopper and you'll also have the doctor's fees, etc to worry about. Most people forget that when you go into the hospital, you don't get only 1 bill. You'll get a bill from the hospital, bills from the lab, bills from the radiologist, the anesthesiologist, the surgeon, etc, etc. It could certainly end up being far more than $15k depending on what all needs to be done and you can bet that those medical providers will go after their money one way or another. I wouldn't even put it past them to start asking for deposits before providing any further care if she's stable and her life is not immediately at risk...it happens.