Question: I’ve heard conflicting views on what’s more critical to include on Medicare claims to ensure swift and accurate payment — CPT® codes or ICD-10 codes. Does the CPT® code determine the reimbursement rate or does the ICD-10 code? I thought it was the CPT® code, but I keep hearing that our practice’s pay could suffer if we don’t use the right ICD-10 codes, so I’m confused. AAPC Forum Participant Answer: The CPT® code on your claim determines your reimbursement rates under Part B Medicare. On the other hand, ICD-10-CM codes support medical necessity for every procedure code on your claim — without them, insurers can’t justify paying your practice for the services the physician performs. Therefore, if you use nonspecific or incorrect diagnosis codes, your pay definitely could suffer. Why? Your insurer might determine you didn’t perform a medically necessary service and thus aren’t entitled to payment for it. Sometimes an ICD-10 code will be the cause of non-payment. Consider this scenario: An asymptomatic Medicare patient makes a visit prior to a colonoscopy to discuss arranging for the procedure. In absence of symptoms or disease to justify the visit, reporting the colon cancer screening code would not be a Medicare-covered service. The patient could be required to pay for the visit by use of an Advanced Beneficiary Notice (ABN).