Which statement is true regarding the use of diagnosis codes for determining medical necessity?

Which statement is true regarding the use of diagnosis codes for determining medical necessity?

• A. Diagnosis codes explain the medical necessity of the service.
• B. Diagnosis codes determine the date of service.
• C. Diagnosis codes replace CPT codes.
• D. Diagnosis codes are unrelated to medical necessity.

Answer: (A)

Medical necessity is shown by linking the service to the patient’s diagnosed condition. ICD-10-CM diagnosis codes communicate why the service was needed and are used with the CPT/HCPCS code to determine coverage and reimbursement. That makes the statement about diagnosis codes explaining medical necessity the best choice. They do not set the date of service—the date is the actual day the service was performed, separate from the diagnosis code. They also do not replace CPT codes; CPT/HCPCS codes describe the procedure or service, while diagnosis codes justify why that service was appropriate. And they are not unrelated to medical necessity; they are essential to showing why the service was medically necessary. For example, an MRI of the knee would be supported by a diagnosis such as knee pain due to osteoarthritis, tying the test to a valid medical need.

Medical necessity is shown by linking the service to the patient’s diagnosed condition. ICD-10-CM diagnosis codes communicate why the service was needed and are used with the CPT/HCPCS code to determine coverage and reimbursement. That makes the statement about diagnosis codes explaining medical necessity the best choice.

They do not set the date of service—the date is the actual day the service was performed, separate from the diagnosis code. They also do not replace CPT codes; CPT/HCPCS codes describe the procedure or service, while diagnosis codes justify why that service was appropriate. And they are not unrelated to medical necessity; they are essential to showing why the service was medically necessary. For example, an MRI of the knee would be supported by a diagnosis such as knee pain due to osteoarthritis, tying the test to a valid medical need.