...service(s) may be identified by appending this modifier to the additional procedure or service code(s). 53 Discontinued Procedure: Under certain circumstances,...extenuating circumstances or those that threaten the well-being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure...

...modifier -53 was used for reporting these discontinued services. Prior to 2/22/05: Use modifier -74 when, due to extenuating circumstances or those that threaten the well being of the patient, the physician had to terminate a surgical or diagnostic procedure after the administration of anesthesia...