A CPT Codes 2003 modification the addition of modifier -63 (Procedure performed on infants less than 4 kg) has a greater impact on urology coding because of what it can't be used with than what it can. The new guidelines tell coders to append this modifier when "procedures performed on neonates and infants up to a present body weight of 4 kg may involve significantly increased complexity and physician work commonly associated with these patients." But try appending it to CPT 53025 and you can be sure your claim will be denied. The rationale for designating 53025 (Meatotomy, cutting of meatus [separate procedure]; infant) as exempt from modifier -63 is that "the additional work that modifier '-63' is intended to represent" is already accounted for by 53025.