Current procedural terminology code changes
(1) In this section, “current procedural terminology code” means a number established by the American Medical Association that a health care provider puts on a health insurance claim form to describe the services that he or she performed.
(2) If an insurer changes a current procedural terminology code that was submitted by a health care provider on a health insurance claim form, the insurer shall include on the explanation of benefits form the reason for the change to the current procedural terminology code and shall cite on the explanation of benefits form the source for the change.
See https://docs.legis.wisconsin.gov/statutes/statutes/632/vi/726