The 2016 ChiroCode Deskbook teaches you how to write off disallowed amounts!

Once the claim has been adjudicated and an Explanation of Benefits (EOB) has been received, the disallowed amounts (if required by contract or law) should be deducted from the patient account to accurately reflect their “patient portion.” Only bill the patient the amount which you are legally allowed to bill. Do not write off patient co-payments or deductibles unless the patient has an approved and current Financial Hardship Application on file.