Ideally, you should start comparing insurance policies before your current policy expires. Once you have allowed a lapse in coverage, there may be additional difficulty getting new coverage at a fair price. Remember, insurers look at many factors to figure premium, and these include: age, gender, occupation, credit history and current insurance. A gap in coverage will raise questions that will need to be answered. Did you simply forget to pay a bill, or is there something more serious? Do you frequently allow insurance coverage to expire, and what is the length of the gaps? Longer gaps may indicate that you drive without insurance, which makes you a higher risk person.
If you can plan a change, there are some good times to change auto insurance providers which should net you a reduced premium. For instance, your rates will go down at age 25, so if your insurance is set to expire the month of, or after your birthday, start shopping with your new age in mind. If you know that you are about to move or change jobs, consider changing your insurance provider before hand. It might be harder to get insurance if your move was over a long distance; you will now be an un-established person in a new town, which equals higher rates. Your new occupation can change your rates as well, especially if you begin work in a high risk category, or if you will use your vehicle more than you did before.
But, if your driving record is spotless, you are 25 or older, there have been no major changes, and your rates have either stayed the same or gotten higher, than you might consider now the time to shop for a discount. Some companies will match a policy and its price if you tell them upfront that you are doing this. Smart research and some basic knowledge will assure that you are getting the best insurance coverage for the best price.