Who Is The Largest Car Insurance Company In America? 
For personal auto insurance the largest insurer is Allstate . Allstate has both the largest amount of premium written in the United States , but it also has the most number of insureds . In my opinion this is good and bad . It is good because it is a company that has a branded name to maintain , which means they will strive for good customer service . It also means it has large purse strings , which means it will be less hesitant to pay out on claims . It is bad because they are a national carrier , which means if there is a large disaster elsewhere in the county , it will effect your premiums wherever you reside . Even though large carriers are great , I also recommend looking into some regional carriers because their premiums tend to stay a little more balanced . 