I am trying to figure out the correct way to bill more than 4 diagnosis codes on a claim. I have read that Medicare accepts up to 8 codes electronically and that is dependent on the provider's billing system being able to list that many codes. I have also read that 8 Dx codes can be submitted on a CMS1500 form by adding the additional codes in box 19. Has anyone had any experience with billing this way and do you know if this is acceptable to the Medicare Advantage plans?