(a) Upon the death of an owner of jointly held property:
(1) If, during the deceased owner's lifetime, the deceased owner could have unilaterally reacquired a portion of the property attributable to the deceased owner's contributions without the consent of the other owner or owners, a surviving owner may disclaim, in whole or in part, a fractional share of that portion of the property attributable to the deceased owner's contribution determined by dividing the number 1 by the number of joint owners alive immediately after the death of the owner to whose death the disclaimer relates.
(2) For all other jointly held property, an owner who survives a deceased owner may disclaim, in whole or part, a fraction of the whole of the property the numerator of which is 1 and the denominator of which is the product of:
a. The number of joint owners alive immediately before the death of the owner to whose death the disclaimer relates;
b. Multiplied by the number of joint owners alive immediately after the death of the owner to whose death the disclaimer relates.
(b) A disclaimer under subsection (a) of this section takes effect as of the death of the owner of jointly held property to whose death the disclaimer relates.
(c) An interest in jointly held property disclaimed by a surviving owner of the property passes as if the disclaimant predeceased the owner to whose death the disclaimer relates.
(d) Disclaimers of interests in property not governed by this section are governed by § 606 of this title.