The Maryland estate tax is a transfer tax imposed on the transfer of assets from an estate. The Maryland estate tax is a state tax imposed on the transfer of property in a decedent's estate.The federal government also has its own estate tax. It is currently only imposed on collateral heirs like a niece, nephew or friend. The inheritance tax is a tax imposed on the privilege of receiving property from a decedent. Our guide to estate taxes includes U.S. federal, state, and inheritance tax rules. Maryland is the only state to impose both an estate tax and an inheritance tax.