Question: How do you code for sinus tarsi injection? West Virginia Subscriber Answer: Coding for a sinus tarsi injection is little challenging since the sinus tarsi is neither a joint nor a ligament - it is a space. The area is the soft indentation just in front of the lateral malleolus and contains nerve endings, fat, joint capsule, arterial anastomoses, and five ligaments. You must identify the location where your physician has administered the injection. If your physician administered an injection into the surrounding soft tissue, code 20550 (Injection[s]; single tendon sheath, or ligament, aponeurosis [e.g., plantar "fascia"]), while if it is in the actual sinus tarsi space, which provides the lateral access to the subtalar joint, then you can report the shot using 20605 (Arthrocentesis, aspiration and/or injection, intermediate joint or bursa [e.g., temporomandibular, acromioclavicular, wrist, elbow or ankle, olecranon bursa]; without ultrasound guidance). Tip: Don't forget to include a corresponding J code to get reimbursement for the drug your provider administered.