I am a dual citizen of the US and another country. I collected SSI and was a Medicare beneficiary in the US. Two years ago I left for another country intending to establish permanent citizenship there--before I left, I informed social security that I was leaving. Recently I decided to come back and reestablish permanent citizenship here in the US. After I went to the social security office to set up my benefits again, I received mail from Medicare asking me to pay several months worth of premiums for the time that I was out of the country. How is it possible that I owe this money when I was not in the country to begin with? It seems that this is correctable by a simple written explanation, but who knows how long it will take for them to sort this out. Any advice would be appreciated.