As you know the US Section 877A Expatriation Tax applies to U.S. citizens and “Long Term Residents”. A “Long Term Resident” is an individual who has had a Green Card (as defined by the rules in Internal Revenue Code Section 7701(b)(6) for at least eight of the fifteen years prior to expatriation). This has become a serious problem for Green Card holders who simply move from the United States and and don’t take formal steps to sever their U.S. tax residency. (They must either file the I-407 or use a tax treaty tie breaker election to expatriate. Otherwise they may be in a situation where they have no right to live in the United States (having lost the immigration status) but are taxable on their worldwide income (still being tax citizens).
That said, whether you are a U.S. citizen wishing to renounce U.S. citizenship or a Long Term Resident wishing to sever U.S. tax residency, you do NOT want to be a “covered expatriate“. Generally, (unless one is subject to two exceptions – dual citizen from birth or expatriation between 18 and 181/2 – that are beyond the scope of this post), one is treated as a “covered expatriate” if one meets any one of these three tests: