You'll then create two systems – PPOs for the healthy that can afford it, underfunded HMO for those who can't. Just drop the rebates, and make any secondary in

You'll then create two systems – PPOs for the healthy that can afford it, underfunded HMO for those who can't. Just drop the rebates, and make any secondary insurance be primary. That would make sure the insured group for the public system includes the healthy rich (which makes the pool for those that actually need and can't afford their health).