If you are on your parents' auto insurance policy but living in a different house are you still covered on their policy for an underinsured claim from an accident in which you were the victim?

Need more info... I'm assuming you have a claim for bodily injury? Why are you living in another house and how long have you been living there? (If it is determined that you now have a separate residence entirely, i.e. not away at college, the insurer will likely NOT deny any claim - that COULD be construed as bad faith - but they can and surely WILL remove you from the policy for any future claims. You said parents' (plural) and not parent's (singular), so I'm assuming your parents are not divorced and not living with one of the parents.