Miss. Code Ann. § 27-9-59

The estate tax law of this state shall remain in force and effect so long as the government of the United States retains in full force and effect as a part of the revenue laws of the United States a federal estate tax, and this statute shall be repealed as and when the government of the United States ceases to impose an estate tax. Wherever possible the terms of this statute shall be construed in conformity with similar provisions of the estate tax law of the United States.