A member who contributes to the member investment plan shall have the eligibility requirements of section 81 except as follows:

    (a) The age 55 requirement of section 81(1)(a) shall not apply.

    (b) The 10 years of credited service requirement of section 81(1)(b) shall be 5 years if the member is working as a public school employee and the member received credited service in each of the 5 school fiscal years immediately preceding the retirement allowance effective date.