State laws do not generally require you to list your spouse on your auto insurance policy but most insurance companies will. In fact, insurance companies will want you to list every licensed person in your household on the policy, including your mother, aunt, or children or legal driving age. The reason they require this is because statistics have shown that anyone in the home who drives may have cause to use the vehicle at one time or another, and listing them on the policy helps the insurance company protect your vehicle investment a little better.
On the other hand, you may be able to have your spouse specifically excluded from your car insurance policy. If you do not want or need your spouse listed on the policy, contact your car insurance provider and ask them about the procedure for excluding a licensed driver who lives in the home. Unless the state laws specifically require the person to be listed, your insurance company can add their name to the exclusion list. If your spouse does not have a drivers license, they do not have to be listed on the policy, and trying to add them could prove to be difficult and expensive.
Keep in mind that excluding your spouse from the policy means that they are not insured if they drive it. If your spouse gets involved in an accident and are found to be at fault, the insurance company will deny the claim on the grounds that the spouse should not have been driving the vehicle. Similarly, if your spouse is excluded and is hit by someone else while driving, that person's insurance company will pay the claim for the same reason. In general, it is a good idea to add your spouse to the policy, even if he or she only drives the vehicle on rare occasions.