Nope it's not a requirement that they are on all policies you sign a paper when you have your auto insurance wrote that you either want it or reject it; there is a paper you check either box. It is SUPPOSE to be offered and EXPLAINED to you and you either choose to take it or not. I think my UIM Policy is about $26.00 every 6 months. Thank GOD I had it or I would totally screwed! She was only wrote for a ticket for running a stop sign! Never was a ticket wrote for her driving without insurance or NOTHING; she got off easy and was able to walk out of her car; me on the other hand wasn't and now I have a PERMANENT disability in my right foot and ankle. I can only wear certain shoes and had to buy $400.00 a piece insoles for my sneakers and closed toed shoes so that I can/could wear them! I encourage everyone to take this on your policy it really can change your life in one second and you can't always rely on the other driver to have enough insurance if any at all!