For a couple of reasons. We take assignment on some Medicare orders, depending on the products. (Please inquire if you need to know for certain prior to submitting your order.) We do take assignment on Blue Cross Blue Shield orders, but in many cases there is a CO-PAY due. Until we know if you have a CO-PAY and what the percentage is, we automatically charge a 20% CO-PAY. Generally, we check your CO-PAY percentage before charging your account. If your CO-PAY is less than 20%, you will receive a check from us from St. Louis Medical Supply for the difference. If your CO-PAY is more, you will receive a bill. Also, especially at the beginning of the year many people have deductibles that have to be paid before coverage by insurance companies. If you have insurance related questions feel free to email our insurance billing department.