My question involves estate proceedings in the state of: Pennsylvania
My grandmother's property was put under joint tenancy with right of survivorship with my father a few years ago to help with my grandmother's estate planning. My father died before she did however. I am a bit confused about this whole thing.. In my research it is my understanding that joint tenancy with right of survivorship would indicate that my father's interest in the property would simply evaporate and my grandmother would then own the whole property. However, I am being told that there is inheritance tax involved in this that my grandmother would need to pay as my dad's portion is transferred back to her? I don't understand why if so. Can anyone tell me if this is the case? Everything I've read seems to indicate otherwise.

