As I wrote on another thread, go through each bill and make sure this person or group (some doctors & nurses use a billing companys) actually treated you.

I have found between 5-10% of all medical stays my family has had, not single day issues, have been bogus overbilling. if you don't recognize a doctor sending you a bill, find out how this person treated you.

Since recognizing this trend we make it mandatory to get business cards from every nurse or doctor and who they bill through. If they don't have one we take down their info on a sheet we made for tracking

My most recent example is last year I spent a week in the hospital. I got a bill for $400 from a doctor I did not recognize. After challenging the bill, it turns out all he did was review my chart at the nurses station one night and billed me for his consult.

But you got 50% off your bill, your way ahead already.