"For imposing Taxes on us without our Consent." From the Declaration of Independence - item 17.
From The Christian Science Monitor - March 19, 2010:
If you ignore this mandate and don’t get health insurance, you’ll have to pay a tax penalty to the federal government, beginning in 2014. This fine starts fairly small, but by the time it is fully phased in, in 2016, it is substantial.
An insurance-less person would have to pony up whichever is greater: $695 for each uninsured family member, up to a maximum of $2,085; or 2.5 percent of household income.
There are exceptions. Certain people with religious objections would not have to get health insurance. Nor would American Indians, illegal immigrants, or people in prison.