Generally speaking, when parties obtainproperty through rights of survivorship they avoid inheritance tax.  That is because you are really not "inheriting" property from another party.  The property passes to you by operation of law, meaning it does not pass through an estate of the decedent.  It passes outside the estate.  Only property that passes through an estate is subject to inheritance tax.  It is true that generally property with rights of survivorship is held between married couples but siblings often hold it that way as do many other types of people who plan well.  If you need to do any estate planning then you need to speak with someone in your area.  Good luck.