There are only a few states in the US that require insurance companies to offer glass replacement without a deductible (waive the deductible) and it is mainly for windshield replacements or repairs as a part of a motorist's Comprehensive coverage. This is typically not even an offering as it is understood that all Comprehensive policies in that state waive the deductible for windshield replacement.
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. Thus, without needing to pay a deductible you can call this a "free" windshield replacement.
In these states your insurance company is required by law to repair or replace your windshield with no deductible charged—as long as you have Comprehensive insurance on your vehicle. Florida and Massachusetts only fully cover windshields, but Kentucky and South Carolina cover all glass replacement with no deductible.
Many CarInsurance.com companies offer a Full Glass or 0 Glass Deductible option that is available instead of selecting a deductible when the windshield is broken or damaged. The states in which you can choose to zero or minimal glass deductible include Arizona, Connecticut, Michigan, Minnesota and New York.
If your windshield has been cracked or broken so that it needs repaired or replaced than you should make a claim through your comprehensive insurance policy. Even if you do not live in FL, MA, SC or KY you can always ask your insurance carrier if they can waive the deductible for a windshield claim. Some insurance companies will waive the deductible for windshield repairs or replacements if their underwriting guidelines allow them to so.