if your provider is focusing on those shoulder hip elbow and knee joint injections the 20550 would not be the correct code. you would need to look into the 20610 for large joint and 20611 if guidance was used. Medium joint is 20605My doctor is billing doing multiple bilateral injections on shoulder, hip, elbow and knee. Is the correct coding 20550 with modifier 50 or 20550 x 30 (as this is the total units being done)?