More than a quarter of young adults currently live at home with their parents. And this type of living arrangement has been modestly on the rise since our last recession. Many in this group reluctantly stayed, or moved back, home during tough economic times, but now are warming up to the idea. They don’t want to leave comfort of a childhood bedroom complete with throwback band posters. Or, they realized the fiscal advantages of extending their stay in the nest.

One such advantage is a better price on auto insurance. In some cases, a significantly better price.

A recent study by found that U.S. drivers aged 18 to 24 could pay eight percent more, on average, for their own insurance policy than they would pay for their portion of a family policy. And, this discrepancy in cost was found to be more than 50 percent for certain types of drivers in some states.

This is not to say that adding a young driver — or anyone for that matter — to your existing family policy won’t bump up the premium significantly. Adding a new, or somewhat new, driver can increase your average annual premium by roughly 80 percent.

Younger drivers are simply more expensive to insure compared to their parents. With only a few years under their belts (literally) to build a reliable driving record and a solid credit history — less experience spells greater risk for an insurance company.

Within a family policy, the high risk value of a younger driver living with their parents is evenly spread across everyone the policy covers. This lessens the financial effect of risk for each individual, ultimately lowering the otherwise high cost of insurance for young adults.

Although the financial benefit of sharing insurance with your parents does taper off with age, theoretically, an adult child could remain on the family plan indefinitely. Unlike other types of insurance, there is not currently a cutoff age for auto insurance — as long as the “child” never leaves the nest. In fact, many insurance companies will prefer or require all licensed family members under one roof to be listed on the same policy.

Of course, there are plenty of factors to consider before purchasing auto insurance — price being just one. Always do your research and weigh the options to find a policy (and living situation!) that suits your unique needs.

Does your family have a shared auto insurance policy? We want to hear your thoughts in the comments below!