Comprehensive car insurance will typically cover hail damage to your vehicle. This type of coverage pays for damage caused by events outside your control, like hail, theft or vandalism. Note that liability-only insurance won't cover hail damage because it only pays for the other driver's costs if you're at fault in an accident.
After you pay your deductible, comprehensive coverage will help pay to repair dents or a broken windshield from hail. File a claim as soon as you notice any dents. However, if the damage seems superficial and only requires paintless dent repair, it might not be worth filing a claim. Get a second opinion from a reputable auto body shop before making a decision, as even minor dents can sometimes cost hundreds of dollars to repair.