According to the North Carolina Driver's Manual insurance points in North Carolina can differ depending upon your insurance company and their rating system, so contact your insurance provider to find out about their particular point system.
If your insurance company gives insurance points according to the Safe Driver Incentive Plan (SDIP) than you should be able to get information regarding this scheme from both your insurance carrier and the North Carolina Department of Insurance.
SDIP (insurance) points are charged following traffic law convictions and at-fault accidents. Insurance points accumulated during the period of the 3 years preceding the date of application or the date of preparation of renewal of the insurance policy are what is looked at by the insurance company. This 3 year period can also be called the "experience period."
Insurance points are different than DMV points that the NC DOT puts on your driving record for various traffic offenses. If you want to find out information on how long DMV points remain on your driving record, contact the NC Division of Motor Vehicles.