N.Y. Est. Powers & Trusts Law § 2-1.12

§ 2-1.12 Credit shelter formula bequests\n If: (a) the decedent dies after January thirty-first, two thousand;\nand\n (b) by reason of the death of the decedent property passes or is\nacquired from the decedent under a will executed or a trust created\nprior to February first, two thousand which contains a formula\nproviding, in sum or substance, for a bequest of the maximum amount of\nproperty that can be sheltered from federal estate tax by reason of\navailable credits against such tax; and\n (c) such formula was not amended at any time after January\nthirty-first, two thousand and before the death of the decedent,\nthen, unless the instrument containing such formula specifically\nprovides that there are non-tax reasons for taking the federal credit\nfor state death taxes into account, such formula shall be deemed not to\ninclude a reference to the federal credit for state death taxes.\n