That preference, Balter said, could be a "luxury plan" that provides a much higher level of coverage than they would receive from a traditional Medicare plan. Private insurance companies, she added, could offer those plans and others for people who want more than what Medicare offers.

Balter doesn't believe Medicare-for-all should "force people into something they don't want." She doesn't support the notion that Medicare-for-all needs to eliminate private options for people. The goal, she said, is to guarantee that there is an adequate level of insurance.

"Beyond that, if you want more than adequate, have at it," she said. "Those two things are not mutually exclusive. Our current system shows that they work together very nicely, as do systems in other places around the world. That's the model that I think is going to suit the American context the best."

There is another reason Balter views her plan as a better approach for establishing a Medicare-for-all system: She believes it could have a better chance of receiving congressional approval if Democrats win control of the House and Senate.