If you get ill or injured in the us you could be more than the $20K in debt for hospital bills

If you're on a visa and you lose your job and thus your health insurance, you're probably going back to your home country anyways. I wouldn't worry about medical debt then, they can't pursue you across international lines. Send the hospital AP department an email saying 'hi I'm no longer in the US, I'm in HomeCountry for the foreseeable future' and they're just going to write off the debt and call it a day. Medical debts don't cross national borders