You are interning at a community pharmacy. You get a prescription for a blood pressure medication for a commercially insured patient. When you run the claim, you find that the patient’s insurance prefers mail order and the patient will have to pay a $20 co-pay to get it filled at your pharmacy as opposed to $0 co-pay for mail order. The patient takes the prescription back to fill with the mail order and avoid the co-pay. But now you are left wondering, “How did that happen? Why the difference in co-pay?”