Except for corporations subject to this chapter which are surviving corporations, health care corporations shall before accepting applications from subscribers in a nonprofit health care plan submit to the Commissioner a plan of operating and overhead expenses, operation cost, and salaries paid or to be paid during any current year together with a schedule of its rates to be charged and the amount of health care service contracted to be rendered, which plan, rates, and amount of service shall be first approved by the Commissioner as fair and reasonable before the corporation shall engage in business.