Which member of a defined-benefit pension plan is NOT eligible to make past service contributions?

A member of a defined-benefit pension plan is typically not eligible to make past service contributions if they joined the plan on the day they were hired. Past service contributions usually apply to employees who had previous eligible employment and are looking to buy back pension service credits for the time worked before they joined the plan. Since Cindy joined RST Corp's pension plan immediately upon her hiring, she does not have previous service to credit or buy back, which makes her ineligible to make past service contributions.

In contrast, the other individuals mentioned have circumstances that may allow them to make such contributions. Philip, who worked with a registered pension plan (RPP) at a previous employer, likely has past service that he could consider for contributions to the current plan. George, with 15 years of credited service, might also have options for past service contributions if there were gaps in his employment that he wants to cover. Macey's long tenure over ten years could similarly provide opportunities for contributing towards past service credits, depending on her specific employment history and any previous pension eligibility.