What Happens to Your Sick Leave When You Retire Under FERS? When a federal employee retires under FERS, any unused sick leave is converted into additional service credit using the FERS sick leave conversion chart. This extra service time is then factored into the pension calculation, increasing the final annuity. The sick leave conversion chart for FERS helps employees estimate how ... https://www.federalpensionadvisors.com/post/fers-sick-leave-conversion-chart