In addition to state laws, some car insurance companies may have their own rules and regulations regarding the coverage of teen drivers with learner's permits. For example, some companies may require teen drivers to have a certain grade point average or to complete a driver's education course in order to be covered under the policy.
If you are unsure whether your son with a permit needs auto insurance, you should contact your car insurance company or agent. They will be able to tell you what the requirements are in your state or province and can help you add your son to your policy if necessary.