Following receipt of an initial notice of a member's retirement date and request for an explanation, the retirement system shall, at least sixty days in advance of such retirement date, provide the member a written explanation of such member's rights under this section and an estimate of the amount by which the member's regular monthly base pension would be reduced in the event of the member's election of any of the options available to the member under this section.
For purposes of this section, "eligible retirement date" for a member shall mean the earliest date on which the member could elect to retire and be entitled to receive a pension under section 86.1540.
§ 86.1580, RSMo