....for those who want it, that provides some sort of public healthcare safety net option but allows the private health care system continue to flourish.

Medicare expansion would need to have premiums and co-pays, but these could be adjusted and limited based on income. For instance, a %-based premium/tax of income up to certain IRS-income tax levels. Small co-pays for certain preventative and routine visits - so that people don't abuse the system. Deductibles and/or larger co-pays or co-insurance % for ER and hospital visits, surgeries, pharmaceuticals, etc. Deductibles/co-pays/co-insurance waived or reduced based on certain poverty levels. Expanded Medicare covers only essential and basic medical care and pharmaceuticals. Number of dependents would also affect the premium and deductibles/co-pay/co-insurance levels.

If you don't like the Medicare Option or want coverage for additional medical services, products, and pharmaceuticals, you can opt for private health insurance or supplemental coverage. No need to pay the extra Medicare premium/tax. The expansion of Medicare negates the need to require employers to offer health insurance to their employees. However, employers would be free to offer private health insurance or supplemental coverage benefits to employees, if they so desire.

I'd like government leadership to take a responsible look at Medicare expansion and show how it could be done affordably.