Thanks for the question! There aren’t any state laws that prohibit this option; however, each carrier must file all their rules, guidelines, and discounts with their state’s insurance commissioner. If this type of discount isn’t filed and approved for the carrier, it’s not an option for any of their customers.
To learn more about how to get affordable coverage for a young adult child who doesn’t live at home, check out this article: https://getjerry.com/advice/how-to-get-cheap-car-insurance-for-a-child-not-living-at-home-by-logan-utsman.