Question: The provider documents that a patient had a charley horse. Which code is the most accurate choice? Rhode Island Subscriber Answer: Most likely you’ll turn to M62.831 (Muscle spasm of calf). As you’ve probably already noticed, when you look the condition up in the ICD-10-CM index, you see two different codes. Look to the documentation: Unless the provider has indicated that the condition was caused by an injury, you can rule out S76.11. You’re now left with the musculoskeletal code, which is M62.831.