"For someone wealthy enough that expatriation tax is an issue, it's worth paying someone to avoid it, " says Richard LeVine, an international tax lawyer with Withers Bergman in New Haven, Conn.

FORBES: Congress makes another grab at expats' money.

Ten Facts About Tax Expatriation.

FORBES: With Taxes, Beware Moving And Vacation Homes!

For a remarkably brief period of time this, was a hot topic because Eduardo Saverin, one of the founders of Facebook, was the poster boy for (purported) tax-motivated expatriation.

FORBES: Renouncing One's US Citizenship -- Meaningful Trend Or Visceral Overreaction?

Now, as we near what, likely, will be a tax compromise with higher tax rates for many, it seems that tax-motivated expatriation is likely to rise, albeit from a fairly low base.

FORBES: Renouncing One's US Citizenship -- Meaningful Trend Or Visceral Overreaction?

Libertarians and conservatives, by contrast, explain that expatriation is the result of an onerous tax system that imposes high tax rates and requires the double taxation of foreign-source income.

FORBES: When A U.S. Company Redomiciles To The Cayman Islands, What Lesson Should We Learn?

To avoid being subject to the U.S. estate tax an expat has to live for more than ten years after expatriation or die in 2010--the year in which the U.S. estate tax disappears for one year.

FORBES: Congress makes another grab at expats' money.