That's total administrative cost. Given that (current) Medicare has high administrative costs as well, there's no reason to believe that the US will suddenly do much better with all its regulations.
Either way, whether it is 2% or 8% the bill will be astronomical. You would have to cut health care worker's salaries significantly to make a big dent in it. I'm not saying that shouldn't happen, but you better own up to it.
[1] https://news.harvard.edu/gazette/story/2018/03/u-s-pays-more...