Wis. Stat. § 455.03

A psychologist who is licensed or certified by a similar examining board of another state or territory of the United States or of a foreign country or province whose standards, in the opinion of the examining board, are equivalent to or higher than the requirements for licensure as a psychologist in s. 455.04 (1) may offer services as a psychologist in this state for not more than 60 working days in any year without holding a license issued under s. 455.04 (1) . The psychologist shall report to the examining board the nature and extent of his or her practice in this state if it exceeds 20 working days within a year.