20 CFR § 408.812
What happens to your SVB payments if you are not a citizen or national of the United States and you begin residing in a Treasury-restricted country?
February 18, 2021
(a) Suspension effective date. If you are not a citizen or national of the United States, we will suspend your SVB payments effective with the first full calendar month you are residing in a country to which the Treasury Department restricts payments under 31 U.S.C. 3329.
(b) Resumption of payments. If benefits are otherwise payable, they will be resumed effective with the first day of the first month in which you are not residing in a Treasury-restricted country.