(a) Except as provided in subsection (b) of this section and the Internal Revenue Code of 1986 [
26 U.S.C.
1 et seq.], notwithstanding any other law of the United States, or of any State, territory, or the District of Columbia, no annuity or supplemental annuity shall be assignable or be subject to any tax or to garnishment, attachment, or other legal process under any circumstances whatsoever, nor shall the payment thereof be anticipated
(b)
(1) This section shall not operate to exclude the amount of any supplemental annuity paid to an individual under section
231a (b) of this title from income taxable pursuant to the Federal income tax provisions of the Internal Revenue Code of 1986 [
26 U.S.C.
1 et seq.].
(2) This section shall not operate to prohibit the characterization or treatment of that portion of an annuity under this subchapter which is not computed under section
231b (a),
231c (a), or
231c (f) of this title, or any portion of a supplemental annuity under this subchapter, as community property for the purposes of, or property subject to, distribution in accordance with a court decree of divorce, annulment, or legal separation or the terms of any court-approved property settlement incident to any such court decree. The Board shall make payments of such portions in accordance with any such characterization or treatment or any such decree or settlement.