With regard to the 'tax' imposed for failure to purchase health insurance:
The penalty will be fully phased in by 2016, when it will be $695 for each uninsured adult or 2.5 percent of family income, whichever is greater, up to $12,500. The nonpartisan Congressional Budget Office estimates that 4 million people will pay the penalty that year.
The law, however, severely limits the ability of the IRS to collect the penalties. There are no civil or criminal penalties for refusing to pay it and the IRS cannot seize bank accounts or dock wages to collect it. No interest accumulates for unpaid penalties.
So how can the IRS enforce the mandate? Scary letters and threats to withhold tax refunds.
So, don't overpay your income tax, and the IRS can't touch you.