Most states require car owners to buy a minimum amount of Bodily Injury and Property Damage Liability insurance before they can legally drive their cars. All states have financial responsibility laws. This means that people involved in an automobile accident will be required to furnish proof of financial responsibility up to certain minimum dollar limits. To comply with financial responsibility laws, most drivers purchase automobile liability insurance.
You can buy a non-owners liability SR22 policy if you do not own a vehicle. Otherwise, you can make an SR22 filing in conjunction with your current or new auto insurance policy.
You cannot get a SR-22 without having insurance on your vehicle that is a least the minimum the state is mandating that you carry. The SR-22 is a filing by the insurance company that shows the state that you have certain insurance coverages in place, so you have to buy those insurance coverages in order to have the SR-22 form filed by an insurance company.
You can get a direct insurance quote here to see how much an SR22 policy will cost you.