(a) A member who is participating in the early retirement program and subsequently transfers to a position that generally would not qualify him to participate in the early retirement program, he may, if he already has accrued ten years of credited service in the eligible position, continue to contribute at the rates charged to members working in eligible positions, and continued payment of the rates shall qualify him to receive any benefit provided in the early retirement program.
(b) A member in a position that does not qualify him as a person eligible for early retirement who is transferred to a position so eligible may elect with one year of eligibility to contribute at the additional rate of compensation for which he shall receive full benefits after twenty years of credited service, if that the employee has been eligible and paying at the higher rate for at least ten years. The employee shall be required at the time he becomes eligible for early retirement or at the time he elects to participate, pursuant to section 767(c) of this chapter, to pay retroactive contributions for credited service to the time he makes the election to pay for the difference between the rates for the time he seeks credit. The member shall pay to the System the contributions, the income the System would have earned had the contributions been paid to the System during the period, and the interest on the unpaid balance. If the member elects to pay on an installment basis, the member shall have the maximum of thirty-six months before any retirement benefits are received to pay the contributions and the applicable interest.