If you are an 18 year old that is cited for being a Minor in Possession (MIP) it is likely your rates will raised. How much the rate will go up depends on the variables your insurance company uses. Insurance for motorists under the age of 25 are already consider inexperience and thus a higher risk. With a MIP violation the risk factor is likely to increase.
There is no specific rate increase that can be stated or generalized for all insurance companies. Each insurance company is required to file their rates and rules with your state regulatory body. So the best way to find out how much your rates may rise is to speak to someone at your insurance company or contact the insurance regulator of your state to see what rates are filed with them for your insurance company.
CarInsurance.com prefers you get an auto insurance quote through us to find out how much we can save you on your insurance, even with the MIP.