Do you need to purchase insurance from rental car agencies when renting a car?
The short answer is maybe not. According to Boston-based Liberty Mutual (libertymutual.com), many drivers' personal auto insurance will cover some, if not all, situations during their use of a rental car. To find out what coverage you have, call your agent.
Many credit card companies also offer protection if you use their card to pay for the rental.
If you want to keep your personal insurance out of the equation for fear of rate increases, then you might want to enroll in American Express's Premium Car Rental Protection. For a fee of either $19.95 or $24.95 per rental (as opposed to the rental agency's per-day policies), you'll be covered up to a certain amount for primary theft and damage, accidental death or dismemberment, and medical expenses - without having to first contact your personal insurance carrier. Coverage is worldwide except vehicles rented in Australia, Ireland, Israel, Italy, Jamaica, and New Zealand.
Check with your card company about what insurance it offers before accepting or rejecting the rental agency's policy.
Got a travel-related question? Send it to Hillary Geronemus, travel editor at Body + Soul magazine, at firstname.lastname@example.org.