26 U.S.C. § 684

1. (a)Except as provided in regulations, in the case of any transfer of property by a United States person to a foreign estate or trust, for purposes of this subtitle, such transfer shall be treated as a sale or exchange for an amount equal to the fair market value of the property transferred, and the transferor shall recognize as gain the excess of—
   1. (1)the fair market value of the property so transferred, over
   2. (2)the adjusted basis (for purposes of determining gain) of such property in the hands of the transferor.
2. (b)Subsection (a) shall not apply to a transfer to a trust by a United States person to the extent that any person is treated as the owner of such trust under section 671.
3. (c)If a trust which is not a foreign trust becomes a foreign trust, such trust shall be treated for purposes of this section as having transferred, immediately before becoming a foreign trust, all of its assets to a foreign trust.