In the case of any interest in qualified real property (within the meaning of section 2032A(b)), an amount equal to the adjusted tax difference attributable to such interest (within the meaning of section 2032A(c)(2)(B)) shall be a lien in favor of the United States on the property in which such interest exists.
26 U.S. Code § 6324B. Special lien for additional estate tax attributable to farm, etc., valuation
Amendment by Pub. L. 96–222 effective, except as otherwise provided, as if it had been included in the provisions of the Revenue Act of 1978, Pub. L. 95–600, to which such amendment relates, see section 201 of Pub. L. 96–222, set out as a note under section 32 of this title.