Maryland Code, Tax-General § 13-906

(b)(1) If a person is required to pay inheritance tax the payment of which would reduce the Maryland estate tax imposed on an estate and would entitle the estate to a Maryland estate tax refund, on the written request of the personal representative of the estate, the Comptroller may pay directly to the register, to be applied against the inheritance tax, any Maryland estate tax refund to which the estate would be entitled as a result of the payment of the inheritance tax.

(2) If a person becomes entitled to an inheritance tax refund the payment of which would result in an increase in the Maryland estate tax imposed on an estate, on the written request of the person making a claim for the inheritance tax refund or if a claim for an inheritance tax refund has not been made, the register may pay the inheritance tax refund directly to the Comptroller to be applied against any unpaid Maryland estate tax or additional Maryland estate tax that would become due as a result of the inheritance tax refund.