> why not just let the government run it? Insurer's roles would be marginalized to competing on doing just enough administration and estimating/negotiating cos

> why not just let the government run it? Insurer's roles would be marginalized to competing on doing just enough administration and estimating/negotiating cost/pricing.. They also would still have incentives to cut costs as they get temporary benefits of cost cutting until copied by the other insurers. It's not a lot but it is areas medicare has problems with (and pricing would get harder still without a reference private market) and retaining a private layer is more compatible with the politics of the US even when it is a pure cost.