Any licensee who demonstrates to the satisfaction of the board that he or she is unable to practice medicine due to a disability may request a waiver of the license renewal fee. The granting of a waiver shall be at the discretion of the board and may be terminated at any time. Waivers shall be based on the inability of a licensee to practice medicine. A licensee whose renewal fee has been waived pursuant to this section shall not engage in the practice of medicine unless and until the licensee pays the current renewal fee and does either of the following: