A professional service corporation is a corporate structure that permits a specific group of licensed professionals who practice the same profession to be the corporate owners.  In Washington, certain licensed health care professionals may form professional service corporations.  Additionally, a group of professionals licensed to practice a number of different health care services may combine to form and practice their services through a single professional service corporation or professional limited liability company.  However, they may engage only in the health care services for which they are licensed.

Occupational therapists and physical therapists are licensed by the Department of Health to provide occupational therapy and physical therapy respectively.  These professions are authorized to own stock in and jointly form or practice through a single professional service corporation or professional limited liability company for the sole purpose of providing services within their respective scope of practice.  Physical therapists and occupational therapists are not permitted to join a professional service corporation with other health care professions.

Physical therapists and occupational therapists may own stock in, and render their individual professional services through, a professional service corporation with other health care professionals.