Only way?  nope.

The #1 reason the USA has significantly higher health care costs is not "overhead." Despite the Bernie Bro mantra not all developed nations deliver universal healthcare via single payer. (How many single payer advocates don't even understand what single payer is?)  To be fair, overhead is a factor among many others.

The #1 reason the USA has significantly higher health care costs is that the pay for all the people involved from doctors to medical equipment manufacturers to pharmaceutical companies is much higher than in other countries. Indeed, "inputs" (things) and "payroll" (services) are virtually the entire cost. (Not sure how much you think the folks in the back room pushing paper get paid but its basically peanuts.) No one wishes to taken on these providers of products and services and tell them "you're taking a 30% pay cut immediately". "Single payer" does not overcome that confrontation.