(4) or any election under subsection (h)) with respect to all or any portion of such assets. The Secretary may require calculation and payment of estimated annual taxes on such assets to the extent that the Secretary determines that doing so would best advance the goal of minimizing gaming by taxpayers. (v) Recapture of depreciation and amortization permitted Nothing in this subsection shall be construed to prevent the determination of gains and losses for purposes of this subsection with respect to any asset on the basis of the adjusted basis of such asset (after taking into account any reductions in such basis for depreciation or amortization). (3) Non-readily tradable asset For purposes of this section, the term non-readily tradable asset means any asset which is part of any class of assets with respect to which the Secretary has determined that mandatory annual valuations are inappropriate for purposes of this section. (4) Illiquid taxpayers (A) In general In the case of an illiquid taxpayer which makes the election described in subparagraph (B)— (i) the net unrealized gain of such taxpayer shall be determined by only taking into account the unrealized gains (and losses) on assets other than non-readily tradable assets, and (ii) such taxpayer shall be subject to the requirements of subsection (f) with respect to all non-readily tradable assets held by the taxpayer. (B) Illiquid taxpayer For purposes of this subsection, the term illiquid taxpayer means any taxpayer for any taxable year if the estimated value of all assets other than non-readily tradable assets of the taxpayer as of the close of such taxable year does not exceed 20 percent of the taxpayer’s net worth for such taxable year. (C) Election Any election made under this paragraph shall be made at such time and in such manner as the Secretary may provide and, once made with respect to any asset, may be revoked only with the consent of the Secretary (and subject to such requirements as the Secretary may provide to ensure proper taxation of gains and