(a) In this subchapter:
(1) "Affiliate" has the meaning assigned by Section 823.003.
(2) "Preauthorization" means a determination by a health maintenance organization, insurer, or person contracting with a health maintenance organization or insurer that health care services proposed to be provided to a patient are medically necessary and appropriate.
(b) In this subchapter, terms defined by Section 843.002, including "health care services," "physician," and "provider," have the meanings assigned by that section.