Mo. Rev. Stat. § 456.1110: Power to withdraw.

1. For purposes of sections 456.1100 to 456.1115, and except as otherwise provided in subsection 2 of this section, during the period the power may be exercised, a power of withdrawal shall be treated as a presently exercisable general power of appointment to the extent of the property subject to the power.

2. Upon the lapse, release, or waiver of a power to withdraw property from a trust, the power is treated as a presently exercisable general power of appointment only to the extent the value of the property affected by the lapse, release, or waiver exceeds the greater of the amount specified in Sections 2041(b)(2), 2514(e) or 2503(b) of the Internal Revenue Code.