Question: Our physician documented that a patient was suffering from pain, swelling, tenderness, and weakness in the hands. The doctor provided the diagnosis of myositis, but when I went to the ICD-10 index, I found M60.14, M60.04, and M60.84. Which one should I code, and why? Codify Subscriber Answer: Unless your doctor's note indicates that the cause of the myositis is bacterial in nature, you can immediately rule out M60.04- (Infective myositis, hand and fingers) in this situation. Of the other two codes, M60.14- (Interstitial myositis, hand) is the more specific diagnosis of the two, suggestive of an autoimmune disease or an infection, whereas M60.84- (Other myositis, hand) is a more general inflammation affecting the connective tissues of the hand. So, you would have to determine the exact code by digging deeper into the patient's notes. If the provider has recorded disease or infection, you would probably use M60.14-, but before you use any of these codes, you should consult with your practitioner. Also note that, in each case, you will need a sixth character to indicate which hand is involved; if both hands are afflicted, you will need a code for each hand.