(a) If the retirement annuity of a retirant (or applicable beneficiary thereof) with at least 25 years of total service is less than $750 per month (including any supplemental or additional benefits provided by this article), then the monthly retirement annuity for the retirant shall be increased to $750 per month: Provided, That any year of service while an employee of an institution of higher education may not be taken into account for purposes of this section if his or her salary was capped under the retirement system at $4,800 per year pursuant to §18-7A-14a of this code.

(b) Notwithstanding the provisions of subsection (a) of this section to the contrary, if the retirement annuity of a beneficiary of a retirant who chose option B – 50% joint and survivor annuity as provided in §162-4-5.1.3 and who had at least 25 years of credited service as of the effective date of this section is less than $375 per month (including any supplemental benefits or incentives provided by this article), then the monthly retirement benefit for the beneficiary shall be increased to $375 per month: Provided, That any year of service while an employee of an institution of higher education may not be taken into account for purposes of this section if his or her salary was capped under the retirement system at $4,800 per year pursuant to §18-7A-14a of this code.

(c) The payment of any minimum benefit under this section is in lieu of, and not in addition to, the payments of any retirement annuity or supplemental or additional benefits otherwise provided by this article: Provided, That the minimum benefit provided in this section is subject to any limitations thereon under §415 of the Internal Revenue Code of 1986, as the same may be amended, and §18-7A-28a of this code.

(d) Any minimum benefit conferred in this section is not retroactive to the time of retirement and applies only to members who have retired prior to the effective date of this section, or, if applicable, to beneficiaries receiving benefits under the retirement system prior to the effective date.