Do a search for "McKinsey health costs" and browse the report. It breaks down category spending in the US vs. other western countries. Yes, admin cost more in the US, but it doesn't add much to the overall costs. The biggest driver of US healthcare spending are out-patient care. The US just does a shit-ton more of it then most countries.

I've seen at least one healthcare economist claim that admin costs account for roughly 25% of spending. Is this in line with what you see there?