Which statement correctly describes the relationship between CPT and ICD-10 in payment for services?

• A. CPT codes describe the service performed; ICD-10 codes justify medical necessity
• B. ICD-10 codes describe the service performed; CPT codes justify medical necessity
• C. CPT and ICD-10 are unrelated in reimbursement
• D. CPT codes alone determine payment without ICD-10

Answer: (A)

The main idea is that CPT codes describe the service performed, while ICD-10 codes justify the medical necessity for that service. Payers determine reimbursement by looking at both: the CPT code shows exactly what procedure or service was provided, and the ICD-10 diagnosis explains why that service was needed for the patient. Without an appropriate ICD-10 code that supports the reason for the service, payment can be denied or reduced, even if the CPT code is correct. Conversely, a valid diagnosis alone won’t pay for a service if the corresponding CPT code for what was done isn’t billed. So billing hinges on the CPT code for the service and the ICD-10 code that justifies its necessity.