10 things your hospital won't tell you - MSN Money: "Crack the code of medical bills and you may find a few surprises: charges for services you never received or charges for routine items such as gowns and gloves that should not have been billed separately. Clerical errors are often the reason for mistakes. One transposed number in a billing code can result in a charge for placing a catheter in an artery versus a vein, a difference of more than $3,900, Stull says.
So how do you figure out if your bill has incorrect codes or duplicate charges? Start by asking for an itemized bill with 'miscellaneous' items clearly defined. Some telltale mistakes: charging for three days when you stayed in a hospital overnight, a circumcision for your newborn girl or for drugs you never received."