structural:reformatting
Dual citizenship

Under certain circumstances there are relevant distinctions between dual citizens who hold a "substantial contact" with a country, for example by holding a passport or by residing in the country for a certain period of time, and those who do not. For example, under the Heroes Earnings Assistance and Relief Tax (HEART) Act of 2008, United States citizens in general are subject to an expatriation tax if they give up United States citizenship, but there are exceptions (specifically 26 U.S.C. § 877A(g)(1)(b)) for those who are either under age 18 + 1 ⁄ 2 upon giving up United States citizenship and have lived in the United States for less than ten years in their lives, or who are dual citizens by birth residing in their other country of citizenship at the time of giving up United States citizenship and have lived in the United States for less than ten out of the past fifteen years. Similarly, the United States considers holders of a foreign passport to have a substantial contact with the country that issued the passport, which may preclude security clearance.