Payments received by a health maintenance organization for health care services, insurance, indemnity, or other benefits to which an enrollee is entitled through a health maintenance organization authorized under this chapter and payments by a health maintenance organization to providers for health care services, to insurers, or corporations authorized under chapter 514 for insurance, indemnity, or other service benefits authorized under this chapter are not premiums received and taxable under the provisions of section 432.1 for the first five years of the existence of the health maintenance organization, its successors or assigns. After the first five years, the payments received shall be considered premiums received and shall be taxable under the provisions of section 432.1, subsection 1. However, payments made by the United States secretary of health and human services under contracts issued under section 1833 or 1876 of the federal Social Security Act, section 4015 of the federal Omnibus Budget Reconciliation Act of 1987, or chapter 249A for enrolled members shall not be considered premiums received and shall not be taxable under section 432.1.