Before each October first, the board shall certify to the state division of budget and planning an actuarially determined amount which will be necessary during the next plan year to pay all the liabilities, including the cost of administration, and any necessary actuarial reserves which shall exist or accrue pursuant to providing the medical benefits options as recommended by the entity. All such premium amounts shall be paid to the executive director at the time that each employee’s wages or salary would normally be paid, but not later than the fifteenth day of the month following. The premium amounts so remitted will be promptly placed by the executive director in the benefit trust fund account. In lieu of the availability of premium deductions the board may establish alternative methods for the collection of premium amounts.