Who Is The Largest Auto Insurance Company In The USA? 
Great question ! There are 5 companies that normally insure about half the market , the number one company being / state Farm . The rest of the top 5 will change around periodically , but they are Allstate , Progressive , Warren Buffets insurance conglomerate -LRB- Geico and others -RRB- , and Farmers . There are several other smaller companies that have a large amount of business , but these are the biggest . Thanks for asking ! 