Despite the majority of current federal employees being enrolled in FERS, CSRS remains prevalent among retirees. This discrepancy arises because FERS was established in 1987, and employees hired before that date remain under CSRS. Consequently, many federal employees who began their careers under CSRS are now retiring, contributing to the higher number of CSRS annuitants.​ https://www.federalpensionadvisors.com/post/how-many-retirees-are-under-csrs