I'm not sure which situation you are asking about, but generally if you are not earning money and can't afford health care, you should qualify for social security and that covers healthcare, rent, basic needs. In general it's mandatory to have health insurance and changes in employment status don't affect your insurance status. Though it's possible to end up uninsured when you are unable/unwilling to pay, but also do not apply for social security payments (however I believe that's more an active choice than a real risk).

As a student for example it's mandatory to get insurance to be enrolled in university. Cost for students that are no longer covered by parents (above age 24 iirc) is close to 100€ per month.