Section 5000A of The Affordable Care and Patient Protection Act (aka Obamacare), reads as follows:
“(g) Administration and procedure
(1) In general
The penalty provided by this section shall be paid upon notice and demand by the Secretary, and except as provided in paragraph (2), shall be assessed and collected in the same manner as an assessable penalty under subchapter B of chapter 68.
(2) Special rules
Notwithstanding any other provision of law—
(A) Waiver of criminal penalties
In the case of any failure by a taxpayer to timely pay any penalty imposed by this section, such taxpayer shall not be subject to any criminal prosecution or penalty with respect to such failure.
(B) Limitations on liens and levies
The Secretary shall not—
(i) file notice of lien with respect to any property of a taxpayer by reason of any failure to pay the penalty imposed by this section, or
(ii) levy on any such property with respect to such failure.”

Read clearly, the Government cannot prosecute you for wilflully refusing to pay the tax. But it can prosecute you for filing a false return. Thus, taxpayers will. if they can figure out whether they fall into the category of being liable for the tax, be subject to possible criminal penalties if intentionally file a false return. So, you can’t lie on the return, however, they can’t prosecute you for innocent mistakes. And there are exceptions to the Act and calculations that will need to be made (yet another schedule to attach to your 1040). So, assuming that you report the tax on your return, what if you refuse to pay? The law is clear, the Service cannot enforce the tax by lien or levy or penalty. So, they cannot assess failure to pay penalties, they cannot assess wilful failure to pay penalties, they cannot garnish your wages, and they cannot put a lien on your house. They can call you and they can presumably offset against your tax refund. It will be interesting to see if the Government can offset against other government payments like social security. Normally it can’t. So, that will be an area of potential litigation. Now be forewarned there are some tricks up the Government’s sleeve here. First, when you send in a payment for your 1040, the government can apply it however they want to apply it unless you specify what it can be used for. Thus,if you intententionally do not want to pay the tax you would who have to not on the check that the payment is going to income taxes only, not to penalties under Section 26 USC 5000A. Otherwise, you send in your check net of the mandate payment and the service first applies it to the mandate and sends you a bill for the other taxes due. But assuming you do this, the Government would have to jump through a lot of hoops to collect the tax. And the Supreme Court has already ruled that the Anti-Injunction Act does not apply to the 5000A penalty. Thus, if the Government did try to set off against other Government payments to collect the tax, you could theoretically go to the US District Court and get an injunction to stop them if you have grounds for an injunction and you would also have the right to sue for refund should they grab enough to fully pay the tax. The Government still would have a right to sue you on the deficiency and convert it to a judgment and then collect it as a judgment, but again the prohibition in the Statute would then raise a whole set of issues as to whether compulsion that can be used to collect a judgment can be used to collect this tax. In other words, there is a tax which the Government can’t really collect, but might with a lot of effort and money be able to somehow get a right to collect it, maybe. Further the Code section puts the money in the Treasury and not to insurance pools and the like, so it won’t keep the premiums down for those who do buy insurance. This provision is unprecedented in many ways, and a penalty that the IRS can’t enforce by the usual means of terror is just one of those ironies.