&gt; Single payer is not a existing program today.<p>Sanders explicitly says that his &quot;single payer&quot; plan is &quot;Medicare for all&quot;. Medicare <i>is</i> an existing program. It hasn&#x27;t been a single-payer system for quite a long time, though; it has been -- longer than the ACA has been around -- a lot like a federalized, rather than state-based, version of the ACA with subsidized private plans but with a public default option.