Question: Encounter notes indicate that the ED provider treated a patient for “laceration, peroneal muscle group, L lower leg” and “tendon strain, peroneal muscle group, L lower leg.” What is the correct coding for these diagnoses? Should I use one ICD-10 code or two? Or more? Texas Subscriber Answer: You should report a pair of ICD-10 codes to represent this patient’s injuries. First, report S86.322 (Laceration of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, left leg) to represent the laceration; then, report S86.312 (Strain of muscle(s) and tendon(s) of peroneal muscle group at lower leg level, left leg) for the tendon strain. Explanation: There is no combination code for these two conditions, so you’ll need to report two diagnosis codes to most accurately represent the patient’s condition. Also, for future reference, the peroneal muscle group involves tendons that run along the back of the fibula, while the peroneus longus starts higher on the leg and runs all the way under the foot.