Sec. 1. Except as provided in this chapter, a health maintenance organization shall deposit with the commissioner or, at the discretion of the commissioner, with any bank or bank and trust company or other trustee acceptable to the commissioner through which a custodial or controlled account is used:
(1) cash;
(2) certificates of deposit;
(3) United States government obligations acceptable to the commissioner;
(4) any other securities acceptable to the commissioner; or
(5) a combination of items described in subdivisions (1) through (4);
which at all times must have a value of at least five hundred thousand dollars ($500,000).