Any person who practices medicine for no fee, for at least one hundred hours per year at a public health facility, as defined in section 20-126l, or in connection with a mobile health clinic that provides health care services to individuals of this state, and does not otherwise engage in the practice of medicine, shall be eligible to renew a license, as provided in subsection (b) of section 19a-88, without payment of the professional services fee specified in said subsection (b).