Wisconsin Statutes Regulation and Licensing (Ch. 440 to 480) § 448.961. License required

(1) Except as provided in s. 448.962(1), no person may practice occupational therapy, designate himself or herself as an occupational therapist, claim to render occupational therapy services, or use the abbreviation “O.T.” or “O.T.R.” after the person's name unless the person is licensed as an occupational therapist or holds a valid occupational therapist compact privilege.

(2) Except as provided in s. 448.962(2), no person may assist in the practice of occupational therapy, describe himself or herself as an occupational therapy assistant, claim to render occupational therapy services as an occupational therapy assistant, or use the abbreviation “O.T.A.” or “C.O.T.A.” after the person's name unless the person is licensed as an occupational therapy assistant or holds a valid occupational therapy assistant compact privilege.