You are correct that this is an increasingly common occurrence that a child splits their time between two household and parents; however there is not necessarily one acceptable remedy provided by the insurance industry of how insurance companies will handle this situation.

In general, most insurance companies want to know who resides in your household. From there most insurance companies will want you to either list that person as either 'eligible' to drive or 'excluded' from driving. If you want your son to be covered by your insurance policy you will need to inform your insurance company that he has obtained his license (or permit) and most likely they will require you to place him as an eligible driver on the policy since both your house and his mother house are considered primary residences for him.

When licensed teenagers split time between divorced parents it is a common question of which parent should include the teen on his or her auto insurance policy. Many insurance providers suggest the parent, who has custody of the teen the most, should add the child to his or her policy. In cases, where the child lives at both parents' houses, even when the child is attending school, then both parents may need to insure the child. We suggest you contact both insurance companies involved to ask their specific guidelines since it can differ from one insurer to the next, even though you are in the same state.

If the same company insures both parents, the teen will normally be covered by both parents' policies, regardless of whether the teen is listed as a driver on either policy. That is because some insurance policies define "an insured" as a person related to you by blood, marriage, or adoption who is a resident of your household. Since not all policies are the same though you will need to read through your policy language and/or contact your insurance company for details if you and your son's mother are insured by the same carrier.

Some insurers require all drivers be named on both policies, no matter how much time they spend in a household. If your teen has access to your car and drives it even occasionally, you might be required to list the teen on your auto policy. His mother's insurance company may also require this of her if he sometimes drivers her car.

As you can see while this is a common situation, differ insurance companies have different guidelines on how to handle it. Some may require that he be placed on the insurance policy while other carriers may not. He may thus be required to be insured by one or both households once he is licensed.

Since he just recently turned 16 if you are in a state that has a graduated licensing system we would recommend you contact your insurer while he is still in his permit or learner's license stage to figure out what will be required of you and his mother's household so that he will be properly insured when driving a vehicle at either residence.