Timing your retirement date
Your FERS retirement date sets three things. It controls when your annuity starts, your final month’s pay, and your lump-sum annual leave payout. A few days can move real money. For most FERS employees, the last day of a month is the strongest date.
9 min read · By RetireCiv Editorial · Updated June 24, 2026
Why does your retirement date matter?
The date you pick is one of the few retirement choices with an immediate dollar effect. Most of your pension is already set by your High-3 and years of service. The date fine-tunes the edges.
Three things move with the date. Your FERS annuity starts on a fixed schedule tied to the month. Your final paycheck covers only the days you actually work. And your unused annual leave converts to a one-time cash payment.
This lesson covers a voluntary, optional retirement. Involuntary separations can follow different start-date rules. The leave payout works much the same either way.
Get the date right and three things line up. You collect a full final month, start the annuity the next day, and cash out leave at the top rate. Get it wrong, and you can leave days of pay behind.
Why does your federal retirement date matter?
The date sets three things. It fixes when your FERS annuity starts, how much of your last month you are paid, and your lump-sum leave payment. Your pension is mostly set by your High-3 and service, but the date fine-tunes the transition. Choosing well can capture a full final month of pay and a larger leave payout.
Does the day of the month really change how much I get?
Yes, more than most people expect. A FERS annuity starts the first day of the month after you separate, no matter which day you leave. So leaving mid-month means your salary stops but the annuity still waits until the first. Retiring on the last day of the month avoids that gap. Your leave payout and first COLA also shift with the date.
When does a FERS annuity start?
A FERS annuity begins to accrue on the first day of the month after you separate. The day you pick inside the month does not change that start date. OPM applies this rule to FERS retirements.
That single rule drives the advice you hear: retire on the last day of the month. You earn salary for the whole month, and your annuity starts the next day. There is no gap between your last paycheck and your first annuity accrual.
The last working day is often used too. If the final day of the month falls on a weekend, the last business day still works, since you separate within that month. Either way, the annuity starts the first of the next month.
Why the last day of the month wins
When does a FERS annuity start after you retire?
Your FERS annuity begins to accrue on the first day of the month after your separation date. The specific day you retire within the month does not move that start. Separate on the 15th or the 30th, and the annuity starts the first of the next month either way. That is why retiring on the last day of the month is the common choice.
What is the best date to retire under FERS?
For most FERS employees, the last day of a month is the strongest date. You are paid your salary through that final day, and your annuity starts the next day with no gap. Leaving earlier in the month gives up salary for the remaining days without starting the annuity any sooner. The exact best date can also depend on your leave balance and the leave year.
Is FERS different from CSRS on the retirement date?
Yes. Under CSRS, retiring on the 1st, 2nd, or 3rd of a month makes the annuity begin the next day. So CSRS retirees often leave early in the month. FERS has no such rule: the annuity always starts the first of the following month. That difference is why FERS advice points to the end of the month and CSRS advice to the first few days.
Why retiring mid-month costs you
Retiring mid-month usually leaves money on the table. Your salary stops the day you separate. The annuity does not start until the first of the next month. Those in-between days pay nothing from either source.
Picture two dates in the same month. Retire on the last day, and you are paid for the full month, with the annuity starting the next day. Retire on the 15th, and you give up roughly two weeks of salary while the annuity start date does not budge.
This is not a penalty in the pension formula. Your monthly annuity is the same either way. You simply collect fewer days of salary in your final month, for no offsetting gain.
Same month, two retirement dates
| You retire | Final-month salary | Annuity starts |
|---|---|---|
| Last day of the month | Paid for the full month | First of next month |
| Middle of the month | Paid only through that day | First of next month |
Why is retiring at the end of the month better for FERS?
Your FERS annuity starts the first of the next month no matter when you leave. So the end of the month captures the most salary before that start. Retiring on the last day pays you for the full month and begins the annuity the next day. Any earlier date gives up salary without moving the annuity start.
Do I lose pension money if I retire mid-month?
Your monthly pension is not reduced for retiring mid-month; the formula is the same. What you lose is the salary for the rest of that month, since the annuity does not start until the first regardless. So it is lost salary, not a smaller pension. Over a single month, that can still be one or two weeks of pay.
How is your lump-sum annual leave payout calculated?
At separation, you receive a lump-sum payment for all unused annual leave. OPM calculates it as the pay you would have received had you stayed and used the leave. It is a one-time cash payment, taxed as ordinary income.
The agency projects your leave forward. Starting the first workday after you separate, it counts your hours across future workdays and holidays until the leave runs out. Each hour is paid at your applicable hourly rate.
This includes leave above your ceiling. Most employees can carry over up to 240 hours of annual leave into a new leave year. Any use-or-lose hours above that, not yet forfeited, are still paid in the lump sum when you retire.
One timing lever sits inside the projection. If a pay raise takes effect during the projected leave period, the hours after it are paid at the higher rate. So a date that pushes your leave across the January pay adjustment can raise the payout.
How is the lump-sum annual leave payment calculated?
Your agency multiplies your unused annual leave hours by your hourly rate. The result is what you would have earned had you stayed and used the leave. It projects the hours forward from your separation date across future workdays and holidays. The payment is a one-time lump sum, taxed as ordinary income in the year you receive it.
Do I get paid for use-or-lose annual leave when I retire?
Yes. Use-or-lose leave above your carryover ceiling that you have not yet forfeited is included in the lump-sum payment. So leave you could not have carried into the next year is still cashed out at retirement. That differs from a normal year, where unused leave above the cap is lost. Retiring lets you convert it to pay.
Can a pay raise increase my leave payout?
It can. The payout projects your leave forward as if you stayed. So any pay raise during that projected period applies to the hours after it. A date that pushes your leave across the January pay adjustment pays those hours at the higher rate. The effect grows with your leave balance.
What else changes with your retirement date?
Beyond the annuity start and the leave payout, your date affects three more numbers. It sets the years of service in your formula, your unused sick leave credit, and your first cost-of-living adjustment. Each nudges your benefit by a small amount.
Working a little longer can add service to your pension and lift your High-3 if your pay is rising. Even one more month of service counts toward the formula.
Sick leave converts to service credit. Every 174 hours of unused sick leave adds a month of service, so your date sets how much sick leave is on the books. The sick and annual leave lesson covers the conversion in detail.
Your first cost-of-living adjustment is prorated by the number of months you were retired during that year, so retiring earlier in the year captures a bit more of it. OPM prorates the first increase this way. Keep in mind FERS COLAs generally begin at age 62.
Does my retirement date affect my pension amount?
Indirectly, yes. Your date sets the years of service in the formula and can affect your High-3 if your salary is climbing. Working to a service milestone, or one more month, can raise the pension slightly. Unused sick leave on your date also converts to extra service credit. The base formula does not change, but the inputs to it do.
How does sick leave affect my retirement date?
Unused sick leave is added to your service as credit, at 174 hours per month of service. Your retirement date fixes how many sick-leave hours you have banked. Leaving with more unused sick leave adds more service credit to your pension. It is a reason some employees avoid burning sick leave in their final years.
Is my first FERS COLA reduced?
Your first cost-of-living adjustment is prorated by how many months you were retired that year. So a partial year earns a partial increase. Retiring earlier in the year captures a bit more of that first COLA. Keep in mind FERS COLAs generally do not begin until age 62.
How to choose your retirement date
Choosing a date comes down to stacking a few rules. Start with the last day of a month, so your annuity begins the next day. Then check whether a leave-year or pay-raise date improves your lump-sum payout.
Watch for a milestone. A few more weeks could earn another full year of service, or carry you past age 62 with 20 years. Either one raises your pension, which can be worth more than the date itself.
File early. OPM needs time to process your application, and interim payments cover you until your full annuity is finalized. Filing ahead shrinks the gap before your first full payment.
There is no single date that is right for everyone; it depends on your leave, your service, and your finances. To see how your pension and income look, run your free readiness score. Then confirm the details with your HR or benefits office before you set the date.
How do I pick the best date to retire from federal service?
Start with the last day of a month, so your FERS annuity begins the next day with no gap. Then check your leave balance and the leave year, since the date sets your lump-sum payout. Account for any January pay raise and any service or age milestone within reach. Confirm the final date with your HR office, because your records drive the calculation.
Should I retire at the end of the year or the start of the next?
We lay out the mechanics rather than name one date. Retiring at the end of a leave year cashes out your full leave balance, including use-or-lose hours. Retiring in early January can push projected leave hours past the pay raise, raising the payout. But it delays your first annuity month. The right choice depends on your leave, your cash needs, and your taxes.
When should I file my retirement application?
File well before your separation date, often a few months ahead. OPM needs time to process the claim, and you will receive interim payments while your full annuity is finalized. Filing early reduces the gap before your first full payment. Your HR office can tell you the lead time your agency prefers.