In the state of Kentucky you can get your windshield replaced for "free", meaning no deductible is paid, but you must have KY Comprehensive coverage on your vehicle. If you only have Liability coverage on your vehicle you will have to pay to get your windshield replaced in Kentucky since it is not covered by your auto insurance policy.
So if you have Kentucky based Comprehensive insurance, KY laws state that your insurance company will waive the deductible for windshield repair or replacement, which means no out-of-pocket expense for you.
Kentucky Revised Statute (KRS) 304.20-060 is titled coverage for safety equipment, definition and states:
(1) As used in this section, "safety equipment" shall mean only the glass used in the windshield, doors, and windows, and the glass, plastic, or other material used in the lights required by KRS Chapter 189 on any automobile.
(2) Any automobile insurance policy that provides comprehensive coverage, whether designated as such, or included within a broader coverage, shall provide complete coverage for repair or replacement of damaged safety equipment, without regard to any deductible or minimum amount.
There are only a few states in the US that waive the deductible for windshield replacements or repairs. The states of Florida, Kentucky, Massachusetts and South Carolina waive the deductible and thus are referred to by some as zero deductible states with regards to windshield claims.
In all these states you must first have Comprehensive or glass breakage coverage to have your windshield replaced or repaired without a deductible. Liability insurance does not cover your own vehicle in any way so this part of your car insurance policy would not cover your windshield that was cracked by a rock thrown up by a vehicle as a piece of roadway debris.