Your comprehension skill are lacking.
1. The $2M sum is only a test for eligibility.
2. Tax is payable on unrealized gains, not total assets:
IRC 877A imposes a mark-to-market regime, which generally means that all property of a covered expatriate is deemed sold for its fair market value on the day before the expatriation date. Any gain arising from the deemed sale is taken into account for the tax year of the deemed sale notwithstanding any other provisions of the Code.
There is a $680k deduction, which is unrelated to any primary residence:
The amount that would otherwise be includible in gross income by reason of the deemed sale rule is reduced (but not to below zero) by $600,000, which amount is to be adjusted for inflation for calendar years after 2008 (the âoeexclusion amountâ). For calendar year 2014, the exclusion amount is $680,000