If your dad becomes unemployed and has very little income, he would most certainly qualify for a heavily subsidized ACA health care plan with caps on maximum out of pocket expenses. And that would tide him over until his mid 60s when medicare (and social security) kicks in. Point is, don't stress too much, they will likely be fine. Health care for the poor and elderly in the US is a much more accessible and affordable resource than we are led to believe, especially in a state like MN which has lots of doctors.
