Actually, you can be resident for tax purposes in Spain and be required to pay taxes in both countries. That said, you'll get credits for the dual taxation, so

Actually, you can be resident for tax purposes in Spain and be required to pay taxes in both countries. That said, you'll get credits for the dual taxation, so it's not as bad as it sounds. However, if you're managing to avoid being tax-resident in Spain, then you've really just the IRS to deal with. If you ever fancy renouncing your US citizenship, then you might be able to be not tax-resident anywhere... (see five flag theory: http://en.wikipedia.org/wiki/Perpetual_traveler http://en.wikipedia.org/wiki/Perpetual_traveler) Or if not completely avoiding tax residency, you can at least minimise your exposure for the taxes you do need to pay. Also, tax and healthcare mostly have nothing to do with each other... It's mostly your residency status (which is totally unrelated to Tax residency oddly). You can be resident in a country for tax purposes, but still not be eligible for Heath care or other social services... Hope that helps somewhat.