Nearly half (about 47%) of healthcare in the U.S. is government-paid, although via a variety of different programs. The USA also has quite lavish benefits in a variety of other ways.

Of course, that is mostly paid for via massive amounts of debt, not from savings of military spending. But government spending on healthcare is more than twice (2.5 to 3 times) that of military spending. So slashing military spending to zero would just mean the amount of government-provided healthcare spending could go from 47% to 56% or so. (Not taking into account that a lot of "military spending" is actually healthcare spending!)