You will have to call your specific insurer to find out for sure. It's probably different for every company and vehicle policy. For me (with State Farm) each airbag only got me $10 discount per 6-month term. I informed them when I removed the driver air bag, I still need to call and let them know that I've also removed the passenger air bag now though. An extra $20-$40 a year is better than the risk of having your policy denied in the event of an accident.