The problem with which this study is concerned is that of determining the optimal transfer of property from a decedent to his surviving spouse. A secondary problem addressed is whether equity between common law states and community property states in the application of the estate tax provisions has been achieved through the allowance of the marital deduction. From this analysis decision criteria were developed to aid taxpayers and their advisors in determining optimal property transfers to a surviving spouse. Conclusions of the study were the following: (1) The primary concern when formulating an estate plan should be to determine whether any property should be transferred to the surviving spouse. The literature has stressed qualifying transfers for the marital deduction while giving minimal consideration to the wisdom of doing so. This study indicates that in a majority of estates optimal results are obtained by making no transfers to the surviving spouse. (2) Relative after-tax rates of return of the surviving spouse and other beneficiaries are the most important factors in determining optimal transfers to the spouse. This again conflicts with the literature which has emphasized relative estate sizes as the dominant factor. (3) Rates of inflation have minimal influence in determining the size of the optimal transfer. (4) Citizens of common law states are generally favored as opposed to citizens of community property states in the application of the estate tax laws. Citizens of these states have more flexibility in. planning transfers to beneficiaries and may generally do so at a lower tax cost through use of the marital deduction.