A common question parents have about teen insurance is, "Do I need to bother insuring my teen at all?" We can't really answer that: This article isn't intended to provide specific legal advice. You should make sure you understand your state laws and insurance company's policies before you make any decisions in this regard.
But you're looking for a straight answer, so here it is:
Your insurance company knows how old your kids are. They know when they turn 16. Some companies will even add them to the policy automatically. If your teen really won't be driving, make sure to let your insurance company know.
If your teen won't be driving the family car at all, or very rarely, then you can probably get by without insuring the teen. If your teen does get into an accident while not insured, the incident should be covered by the parents' insurance, just as if a friend had borrowed the car. It's unlikely the insurance company would flat out refuse to pay the claim. However, they might make you pay the retroactive premiums since the time that the teen first got his or her license.
There's an important exception to this: If your teen already has a driver's license and has been driving when your insurance policy comes up for renewal and you don't inform the insurance company, they may have a right to refuse future claims if your teen wrecks the car. There's clause that says, in essence, "I didn't lie about any of the stuff that determines how much of a premium you're going to charge me when we signed this policy." Not mentioning a teen driver could be considered a violation of that clause and grounds for the insurance company to refuse the claim. That could cost you a lot of money, so you're much better off insuring your teen.
In case that wasn't enough emphasis, here's a scenario: Your teen rear-ends a Lexus. One with a $50,000 sticker price. Let's be conservative and say the accident does $8,000 in damage to the Lexus. The insurance company refuses the claim because your kid wasn't on your insurance. It doesn't matter what your deductible is: Have fun paying that $8,000 out of pocket. And we haven't even talked about fixing your own car yet. So, be upfront with your insurance carrier.