Will My Auto Insurance Go Down When I Turn 25? 
In Montana the average rate decrease after you turn 25 is $ 200.00 every 6 months depending on the carrier . This does n't factor in if the carrier had a rate increase for your area which then the decrease may not be as much . This also does n't take into consideration your driving history . But in most states and most carriers the rates do decrease after the age of 25 