I know that US tax obligations do not end until form 8854 expatriation statement is submitted. But is the actual date retroactive after that? For example if I complete the form to submit with last tax return this April but had reliquished US permanent resident status last year April 1 would that retroactively make tax obligation end April 1 2015? It does not seem logical that it can mean that taxes due up until time the form actually is submitted since that will be with last tax return which will is submitted in 2016.

Also what prior 5 years does form refer to for statement of meeting tax obligations; i.e if submitting form in 2016 with 2015 return is it for 2011 through 2015 or 2010 - 2015?