NEW YORK (TheStreet) -- When was the last time you looked at your car insurance policy? Better yet, when was the last time you checked to see if you could get a cheaper rate?

Unless you just bought a new car, got married, moved to another state, or added one of your children to your policy, chances are it's been more than 12 years, according to a recent survey by Princeton Survey Research Associates International for

Damian Callender, 34, whose first car was insured through Allstate (ALL) - Get Report with his dad, said he stayed with the company for years. He didn't switch until he bought his second car, when he decided to look around for a better rate.

"I was conditioned through my dad to stick with Allstate," said Callender. After shopping around, though, he found he could pay less for what he wanted at Geico, a subsidiary of Warren Buffet's Berkshire Hathaway (BRK.A) - Get Report. That's not the case for everyone: Buffett himself has said that Geico offers the best rate only about 40% of the time. 

"With insurance I feel like its the cheapest one that you can get and make sure it covers the entire car," said Callender, who sold his car when he moved to New York City.

If you're not ready to sell yours, you can probably still save money on auto insurance just by shopping around.

It's something almost 36% of drivers never do, according to the survey, which identified millennials and senior citizens as the least likely to examine their policies. Another 30% of drivers said they usually wait a few years before seeking new rates, making for a total of about 66% of Americans who never or rarely bargain-shop for their insurance. 

The three main reasons are automatic deductions and policy renewals, procrastination, and confusion about when you can switch, said Laura Adams, a senior analyst for, which offers free rate checks.

"I was really surprised by how many people mistakenly believe that you have to wait until your policy actually expires or the renewal date comes up until you can shop," said Adams. "There's a lot of confusion out there about whether it's beneficial to shop and even if there are any negative consequences."

There's no harm in looking around, she added, and you can change your policy at any time. Even if you prepaid for your old one, your company will refund the money on a pro-rated basis.

And there's no penalty, a fact the survey found that nearly 50% of Americans don't know.Millennials appear to be even more in the dark, with nearly 60% of survey participants saying that weren't aware they could switch policies whenever they chose. 

Even those who do shop around for a new rate tend to stick with the same company: Some 25% of drivers stay with the same company for more than 16 years and 7% stay 30 years or longer.

Even if you don't want to leave your carrier, you can ask your agent whether you qualify for new discounts or a less-expensive policy based on lifestyle changes. Insurers may offer discounts for being married, for instance, going back to school or for being a good student

"We want to make sure our customers' policies meet their needs, and we can't know each and every one of those coverage needs unless we are having a conversation with our customers," said Justin Herndon, a spokesman for Allstate. 

Car owners should review their policies -- and policy needs -- at least once a year to make sure they're getting the best rate, Adams said. 

"If you're not checking in with the marketplace on a regular basis, years and decades will go by and all of a sudden you'll end up overpaying for coverage," she said. "Checking in on a regular basis is really smart because things have changed in your life, probably over the past year and certainly over the past decade."

Nearly 64% of the drivers surveyed actually think it's a good idea to shop for car insurance, but don't consistently examine their policies.
Nearly 62% of them find the process of looking for a new policy time-consuming, 44% say it's frustrating, and 40% find it overly complicated.

"I kind of feel like insurance is a pain in the butt in general," said Callender. "You only use it when you truly need it."

But researching a policy doesn't have to take that much time: If you allot at least one hour each year to examining at least three different rates, you'll have a good chance of finding a cheaper one, Adams said.

"It's smart because not every carrier will evaluate risk the same way -- they're going to look at you as an individual and apply your circumstances to their unique algorithm for how they calculate rates," said Adams. "There's really not one standard. It's very different from carrier to carrier and state to state as well."