ERS members must apply for retirement at least 60 days before their retirement date via the Retirement Online Application System. You should use this application if you want to apply for an annuity which will begin within 30 days of your separation from Federal service.This booklet is for the express purpose of helping you understand how your Pension Plan works, its important provisions and your participation rights. The following chart outlines the requirements for an immediate annuity under the Federal Employees. Retirement System (FERS). Montgomery County offers employees an optional 457B Deferred Compensation Plan. This Plan provides employees with additional tax-advantaged retirement savings. It is imperative that the Employee and. Retiree Service Center (ERSC) receive all of your forms at least 30 days prior to your retirement date. On the member's age, service credit, employment status, and eligibility for retirement.