physician
(2) “physician” includes surgeons, podiatrists, dentists, clinical psychologists, optometrists, chiropractors, and osteopathic practitioners within the scope of their practice as defined by State law. The term “physician” includes chiropractors only to the extent that their reimbursable services are limited to treatment consisting of manual manipulation of the spine to correct a subluxation as demonstrated by X-ray to exist, and subject to regulation by the Secretary;