Medicare requires us to bill any insurance company that could have responsibility for your expenses before we bill Medicare. In fact, Medicare will not allow us to file claims until the other insurer has denied claims. In certain situations, the hospital must consider the possibility that another party may be responsible for your expenses before we bill Medicare. For example, if you were injured in a car accident, at your worksite, or on someone else's property, it is the hospital's responsibility to make sure those claims are filed appropriately. Consequently, we need to have complete information about all insurance coverage you have.