I think you slowly transition to it.For example, first steps might be:Lower the Medicare age to 55. Raise taxes to pay for thisThis will lower prices in the private insurance market by taking the older customers out of the poolAllow the government to negotiate drug pricesTry to get an agreement from private insurance companies to match the Medicare payment rate for services. This would level the playing field, reduce the cost of private insuranceLimit the maximum cost for insurance premiums, copays and deductibles for plans purchased on the exchanges to 10% of adjusted gross income. Raise taxes to pay for thisAllow people over the 55 to stay on their business insurance if their employer provides it, and give business a tax credit for paying for their insurance.Allow anyone under 55 who wants to buy into the Medicare program with the option to do so. This option would be on all ACA exchanges so there would never be a situation where someone had no insurance optionKeep medicaid, the VA and other programsOvertime reduce the age lower, next to 50, then to 45 etc.