Question: An adolescent male patient came in with pain in the right foot around the ankle region, and I am not sure if I should report this with M79.671 or M25.571. Which of the two is correct? Iowa Subscriber Answer: Your code choice in the encounter will very much depend on the exact nature of the patient’s pain. The ICD-10 index has no entry for Pain, foot, though it does direct you to Pain, limb, lower, foot, M79.67-. However, you should not automatically use that code. You would only choose M79.671 (Pain in right foot) if the pain is in the soft tissue of the patient’s right foot, as the M79 codes are used for “Other and unspecified soft tissue disorders, not elsewhere classified.” M25.571 (Pain in right ankle and joints of right foot), on the other hand, is one of the arthropathy codes (M00-M25), which represent problems with the joints. So, you will have to go back through your provider’s notes to determine which of the two codes most accurately describes the patient’s condition. As both codes are Excludes2 codes for each other, it is also possible that you could use both in this situation depending on what your provider has documented.