Section 2A. (a) A tax is hereby imposed upon the transfer of the estate of each person dying on or after January 1, 1997 who, at the time of death, was a resident of the commonwealth. The amount of the tax shall be the sum equal to the amount by which the credit for state death taxes that would have been allowable to a decedent's estate as computed under Code section 2011, as in effect on December 31, 2000, hereinafter referred to as the ''credit'', exceeds the lesser of:

(i) the aggregate amount of all estate, inheritance, legacy and succession taxes actually paid to the several states of the United States, other than the commonwealth, in respect to any property owned by that decedent or subject to those taxes as part of or in connection with his estate; or

(ii) an amount equal to the proportion of such allowable credit as the value of properties taxable by other states bears to the value of the entire federal gross estate wherever situated.

(b) A tax is hereby imposed upon the transfer of real property situated in this Commonwealth and upon tangible personal property having an actual situs in this Commonwealth of every person who at the time of his death was not a resident of this Commonwealth. The amount of this tax is a sum equal to the proportion of the credit which the value of Massachusetts real and tangible personal property taxed in this Commonwealth which qualifies for such credit bears to the value of the decedent's total federal gross estate.

(c) Notwithstanding any other provision of law, the tax imposed by subsections (a) and (b) shall be computed upon the value of any property subject to a power of appointment which is includible in the federal gross estate, notwithstanding that a tax has been paid thereon pursuant to section fourteen of chapter sixty-five.

(d) For the purposes of computing the tax imposed by subsections (a) and (b), the provisions of section three shall not apply.

(e) For the estate of decedents dying on or after January 1, 2003, all references and provisions in this chapter to the Internal Revenue Code or Code, unless the context clearly indicates otherwise, shall be to the Code as in effect on December 31, 2000.