I am, fairly, new to this forum and I just want to ask for any opinion from anyone. My son, recently, had gone through EKG in a hospital. I was surprised when I got the bill. I had to pay $1,109.12 for just the EKG. I know it costs more in a hospital but the thing is, the hospital's billed amount is just $180.75 based on the COB. I talked to the customer service representative and she told me that this is due to the allowed amount, $964.25, being greater than the billed amount. I don't know if that makes sense. The hospital just billed my insurance, which is United Healthcare, for $180.75, but because my plan's allowed amount is $964.25, I have to pay $1,109.12. It appears that I have to pay the sum of the billed and allowed amount. Is this a usual practice of health insurance companies? Any advice will be helpful. Thank you.