On Sunday, January 17—hours before the Democratic presidential debate on NBC—Vermont Senator Bernie Sanders released details of his proposal to replace the entire U.S. health care system with a universal, government-run, single-payer one. In Sanders’ eight-page campaign white paper, entitled “Medicare for All,” the self-described “democratic socialist” outlines his plan’s core principles.

Warren Gunnels, Sanders’ policy director, retained Gerald Friedman, an economist at the University of Massachusetts at Amherst, to come up with a fiscal score of the Sanders plan. Friedman estimates that the plan would require $13.8 trillion in new government spending in the decade spanning 2017 through 2016. Avik Roy of the Manhattan Institute outlines why that estimate is far too low.