What happens if you don't have health insurance, after the new reforms kick into effect?

As I understand it, every US citizen "must have" health insurance one way or another. What happens to people who simply refuse to cooperate? Or can't afford to buy it and don't qualify for government assistance either, or can't afford the government assistance? I can't seem to find an answer anywhere and am curious what the consequences will be. Please no guesses, Obama rants, or other off topic responses, just an answer to the question
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The penalty is around $700 or 2.5% of your income (the larger), which is $2500 if you make $100,000 If your income is below a certain level or if the cheapest insurance would cost 8 percent of your income, no penalty would apply for lack of coverage (more than 3 months without insurance).
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