An Expatriation tax is payable if you are a ‘covered expatriate’ which will apply if:
Your average net income tax for the five years ending before the date of expatriation is more than a specified figure that is adjusted for inflation ($160,000 for 2018.
Your net worth is $2 million or more on the date of your expatriation.
You cannot certify tax compliance.
If you qualify as a covered expat you will be treated as having disposed of your assets the day before your expatriation and will be subject to capital gains tax. The first $699,000 of any assessed gains are exempt and any gains beyond this will be taxed as a short term or long term gain.
The Expatriation Tax is generally only an issue for very high net worth individuals, but the inability to certify tax compliance draws many people, including accidental Americans, into the tax. The exemption of $699,000 will take many out of having to pay any tax, but property or other gains can have an impact. It is essential to take advice before you renounce your citizenship to see if you can structure things to avoid being a covered expat and, if this is not possible, to structure your affairs to eliminate or minimise any taxable gains.