What codes are modifier 63 exempt?

Modifier 63 is used to indicate that a procedure was performed on a patient who is less than 4 years old and was significantly greater than the usual service. Codes that are generally exempt from modifier 63 include certain surgical procedures, as well as codes for evaluations and management services. Specifically, codes in the ranges of 99201-99499 (E/M services) and some specific surgical codes may not require modifier 63. For accurate billing, it's always best to consult the latest coding guidelines or resources.