Marital Deduction A tax deduction that allows an individual to transfer some assets to his or her spouse tax free, creating a reduction in taxable income. A marital deduction is mainly used for the purposes of estates and gifts. Investopedia Says: The Internal Revenue Service has strict guidelines for allowable deductions, so it is important to make sure that you or your accountant adheres to them when making deductions. Related Terms: Adoption Credit Child Tax Credit Community Property Deduction Estate Tax Gift Gift Tax Head Of Household Kiddie Tax Marital Property Write-Off |