If you cross that barrier switching between unemployed and employed, there is mounds of paperwork. I wish I could cite a study, but I'm pretty sure people procrastinate / preventative health measures are less prevalent because of this red type.

For a single individual, if you make $18K gross you make too much for Medicaid. In 14 US states, if you make $0 you make too much for Medicaid.

I don't understand this. Are there 14 states where nobody gets Medicaid?

Not exactly. The ACA included an expansion of the Medicaid program, almost entirely funded by the federal government, that provides coverage to anyone making below the amounts other posted quoted. However, the Supreme Court ruled that states could opt out of this "expansion" if they want, and several states did. In those states they still provide pre-ACA Medicaid services - children, pregnant women, and a couple other groups are covered - but don't have general coverage for low-income people.

Only in states that expanded Medicaid, and that number is too high.