Wis. Stat. § 448.56

(1) WRITTEN REFERRAL. Except as provided in this subsection and s. 448.52, a person may practice physical therapy only upon the written referral of a physician, naturopathic doctor, physician assistant, chiropractor, dentist, podiatrist, or advanced practice registered nurse. Written referral is not required if a physical therapist provides services in schools to children with disabilities, as defined in s. 115.76 (5), pursuant to rules promulgated by the department of public instruction; provides services as part of a home health care agency; provides services to a patient in a nursing home pursuant to the patient’s plan of care; provides services related to athletic activities, conditioning, or injury prevention; or provides services to an individual for a previously diagnosed medical condition after informing the individual’s physician, naturopathic doctor, physician assistant, chiropractor, dentist, podiatrist, or advanced practice registered nurse who made the diagnosis. The examining board may promulgate rules establishing additional services that are excepted from the written referral requirements of this subsection.