(a) The refusal of a health benefit plan issuer to provide benefits to an enrollee for a prescription drug is an adverse determination for purposes of Section 4201.002 if:
(1) the drug is not included in a drug formulary used by the health benefit plan; and
(2) the enrollee's physician has determined that the drug is medically necessary.
(b) The enrollee may appeal the adverse determination under Subchapters H and I, Chapter 4201.