Whether that is true or not depends. Generally, U.S. citizens or long-term residents (green card holders who held lawful permanent resident status in eight of the last fifteen years may be subject to an exit tax upon expatriation. However, the exit tax only applies if you are a "covered expatriate." Covered expatriates are expatriates with (1) a net worth in excess of $2,000,000, (2) an average income tax liability of $172,000 over the last 5 years, or (3) who are noncompliant with the tax code. I would suggest to contact a tax professional who is knowledgeable in this area because a mistake can prove costly. Please contact me if you like to know how the law applies to your specific situation.