(a) As used in this section:
(1) A reference to Section 4980A of the Internal Revenue Code means Section 4980A of the federal Internal Revenue Code of 1986 as amended (26 U.S.C. Sec. 4980A) and also means former Section 4981A of the federal Internal Revenue Code of 1986.
(2) “Excess retirement accumulation” has the meaning given it in paragraph (3) of subsection (d) of Section 4980A.
(b) If the federal estate tax is increased under subsection (d) of Section 4980A of the Internal Revenue Code, the amount of the increase shall be a charge against the persons who receive the excess retirement accumulation that gives rise to the increase, and shall be equitably prorated among all persons who receive interests in qualified employer plans and individual retirement plans to which the excess retirement accumulation is attributable.