Grandfathered in Law and Legal Definition
Grandfathered in is the right or sanction provided in a statute, zoning ordinance, law etc exempting a person or entity from certain provisions contained there in, to maintain their present activities, which will be affected by the new statute, ordinance etc. For example, the Federal Assault Weapons Ban made it illegal to sell and own a semi automatic weapon that was manufactured after the date the law went into effect. Weapons that were manufactured before that date were "grandfathered in" and were allowed to be legally owned and sold.