What changes can be made to Federal law to keep the costs of health care down?

We need to understand that people without health care still show up at emergency rooms, which is needlessly expensive.  Every American must participate in a basic single payer plan that is administered by third party vendors that compete every 3 years to keep the contract.  (3 years allows the public to hold our President accountable).  The amount paid is a sliding fee based on income.  Even those totally dependent on government would be shown they are receiving a reduction in discretionary income to pay into the mandatory system.  The free market would still exist for Individuals and employers to negotiate supplemental insurance policies.