When your car is being repaired, the deductible is due to the repair shop, not your car insurance company.
Many mechanics will collect your deductible from you when the repair is done and you come to pick up your vehicle. In cases like this, your deductible is the final payment due upon completion of the repair, because your car insurance company has already paid the repair shop directly its portion of the repair cost.
Other repair shops will require your deductible amount be paid before they will begin work on your vehicle. In this situation, it's likely that your auto insurance company isn't paying its portion of the repair bill until the car is repaired and your deductible amount has already been met.
When the deductible amount is due varies greatly, so we'd suggest you speak to your insurance adjuster, who is working with the repair shop for the company's portion of the repair. He can tell you exactly when your deductible amount must be paid. If you can't reach the adjuster (they are notoriously difficult to reach), you can simply speak to the repair shop directly about when they will request your deductible amount be paid to them.
Before starting repairs, it is a good idea to make sure you can meet your deductible. If you're unable to come up with the deductible amount, your car insurance company may hold back its payment to the repair shop until you can.
Also, if the repairs have already been done, the repair shop may not release your car until your deductible payment is made and could start charging you a storage fee for holding onto the car. Or they may put a mechanic's lien on your vehicle. (See "What if I can't pay my deductible?")
If your insurance company isn't able to explain to you what to do in this situation or fulfill your car insurance needs, contact a CarInsurance.com agent and they can explain not only insurance terms and claim procedures, but also tell you how they can get you low cost car insurance.