This applies to most anyone but especially to anyone contemplating retiring abroad: Financial Considerations of Moving Abroad | Charles Schwab
Reminder that only about 1+/- % of Americans retired abroad and probably half of those are people who already had dual citizenship and moved “back home”, or were Americans working abroad, with permanent residency in the country, and, often owning a home there, chose to retire there. Contrary to the media, few Americans will retire outside the U.S.