I am a U.S. resident who does not own a car, so I have my own personal non-owner auto-liability insurance policy, which covers me when I drive a rental car. Therefore, I cannot answer your specific question. However, I know that, depending on the booking channel you use to book your U.S. rental, you might be quoted an all-inclusive rate that includes third-party liability insurance.

Hertz appears to provide minimal, primary liability insurance in California to foreign renters, and to all renters with no other insurance in a handful of other states:

"If renting in California:

"Hertz provides no liability protection under the terms of the Rental Agreement to the renter from claims of injury by others against you resulting from an accident. Your personal/business insurance may cover your liability. Exceptions: Hertz will provide primary liability protection up to the statutory minimum limits to international customers (driver's license indicates an address outside the USA) renting in California. Please also refer to Liability Insurance Supplement (LIS) below.

"If renting in Massachusetts, Michigan, New York, South Carolina, Virginia, or West Virginia:

"Upon signing the Rental Agreement, Hertz provides primary liability protection. However, such protection is generally no more than the minimum limits required by individual state law. See Financial Responsibility Limits by State."

Many renters would consider these state minimums to be insufficient coverage.