As of fiscal year 2022, approximately 56% of all federal annuitants—totaling 2,226,760 individuals—were receiving retirement benefits under the Civil Service Retirement System (CSRS), a defined-benefit plan established in 1920. This system continues to serve federal employees hired before 1984 who opted not to switch to the Federal Employees Retirement System (FERS) introduced in 1987. https://www.federalpensionadvisors.com/post/how-many-retirees-are-under-csrs