Yes. If your son or daughter is a member of your tax household, they can join your family plan on the health insurance marketplace, even if they live out of state. However, your child may need to return home in order to access care within your plan’s network. If he or she gets health care services in another state, the providers may be outside your plan’s network and you may have to pay high co-payments or coinsurance. Your son or daughter is also likely eligible to buy coverage in the state where they attend school. If they do so, they would have a greater choice of in-network providers. (45 C.F.R. § 155.305 (a)(3)).