FERS & CSRS Guide

The worst days to retire from federal service

You spend decades earning your pension — and then a huge chunk of its early value can hinge on a single decision most people barely think about: which day you walk out the door. Pick the wrong date and you can forfeit a full month of annuity, spend weeks in non-pay status, and leave thousands in unused leave on the table. Pick the right one and your pension starts the next day with no gap, your leave pays out in full, and your first check arrives sooner. The rules are quirky, they differ between FERS and CSRS, and they change with the calendar. This guide lays out the worst dates to avoid, the rules behind them, and the best 2026 dates — with a calculator showing what your date is worth.

1st
FERS annuity always starts the 1st of next month
OPM
3-day
CSRS rule — retire by the 3rd, annuity next day
OPM
240 hrs
Annual leave carryover cap — excess can be lost
OPM
4–8 wks
Wait for the first annuity check (interim pay)
OPM

1. A financial decision, not a formality

Most people treat their retirement date as a personal milestone. It’s also a financial transaction governed by rigid OPM rules about when your annuity starts and when leave is credited. Get the date right and everything lines up. Get it wrong and you can donate a month of pension and a chunk of leave back to the Treasury — for nothing. The good news: fixing it usually costs nothing but moving the date a few days.

2. The FERS rule

For FERS (and the FERS portion of any annuity), the rule is simple and unforgiving: your annuity always begins the first day of the month after you separate, and it is not prorated.

Separate any day in June → annuity starts July 1
Best FERS date = the LAST day of the month

Retire on May 31 and your annuity starts June 1 — seamless. Retire on June 15 and your annuity still starts July 1, but you got no pay for June 16–30 and your first check is delayed a month. That’s why the last day of the month is always a “best date” for FERS.

3. The CSRS 3-day rule

CSRS and CSRS Offset get a bonus option FERS doesn’t: the 3-day rule. If you separate on the 1st, 2nd, or 3rd of a month, your annuity begins the next day (prorated for days worked). Separate on the 4th or later and it doesn’t start until the 1st of the following month.

SystemBest retirement date(s)
FERSLast day of the month
CSRS / CSRS Offset1st–3rd of the month, or the last day

All days — including weekends and holidays — count toward the 3-day rule. A CSRS employee can retire Friday, Jan. 2, 2027 and have the annuity commence the next day.

4. Three ways a bad date costs you

5. What’s your date worth?

Enter your numbers to see the dollars riding on getting the date right: a month of annuity, your leave lump sum, and any use-or-lose leave at risk.

Best-date payoff estimator

Shows what a well-timed date protects. A month of annuity is what a mis-timed FERS date typically costs. Estimate only.

One month of annuity (mis-timed date)$0
Annual leave lump sum$0
Use-or-lose leave at risk (>240 hrs)$0
Total riding on the date$0

6. The leave-year trap

Here’s the timing most people miss. Annual leave is capped at a 240-hour carryover. If you’ve banked use-or-lose hours above that, retiring at the end of the final pay period of the leave year lets you cash out everything as a lump sum. Retire after the reset and the excess simply vanishes.

Two bonuses for waiting a few days

The 2026 leave year ends around January 9–10, 2027. Retiring at that point (a) cashes out maximum annual leave including use-or-lose, and (b) if timed after the January 2027 pay raise, values every one of those leave hours at the higher new rate. And remember — unused sick leave isn’t paid out but converts to service credit, so don’t burn it before you go.

7. The first-check delay

Your date also affects when you get paid. OPM targets 30-day processing but often runs longer, issuing interim payments of roughly 40–90% of your annuity while it verifies your record. Retiring at the end of the month shortens the wait to about 4–5 weeks; retiring early in the month stretches it to 7–8 weeks. Your leave lump sum usually arrives faster, within a few weeks of separation.

8. Best 2026 dates

These dates land on or near the end of a pay period and honor the annuity-commencement rules:

FERS (last day of month / end of pay period)CSRS (1st–3rd or last day)
May 30May 2 · May 30
June 27Oct 3 · Oct 31
Oct 31 (Oct 30 Fri)Nov 28
Nov 28 · Dec 31Jan 2, 2027
Jan 9–10 (leave-year end)Jan 9, 2027 (leave-year end)

Your ideal date is personal — balance the annuity rules, leave payout, the high-3 and any pending raise, and your own cash-flow needs. Confirm with your HR/benefits office before you file.

9. Frequently asked questions

What is the best day of the month to retire under FERS?

Under FERS, your annuity always begins on the first day of the month after you separate, and it is not prorated. That makes the last day of the month the best day to retire, because your annuity starts the very next day with no gap. If you retire mid-month, say on the 15th, your annuity still doesn't begin until the first of the following month, so you get no pay and no annuity for the rest of that month, and your first annuity check is delayed. The ideal FERS date is one that falls on both the last day of the month and the end of a pay period, so you also capture the final pay period's leave accrual.

What is the CSRS 3-day rule?

CSRS and CSRS Offset have a special rule that FERS does not: if you separate on the first, second, or third day of a month, your annuity begins the very next day, prorated for the days you worked. Retire on the 4th or later and your annuity doesn't start until the first of the following month, creating a gap. So CSRS employees have two good windows, the first three days of the month or the last day of the month, while FERS employees are best served by the last day of the month only. All days, including weekends and holidays, count toward the 3-day rule.

How does retiring mid-month cost me money?

Because a FERS annuity only starts the first of the following month, retiring in the middle of a month means the rest of that month is spent in non-pay status: no salary and no annuity. For example, retiring June 15 means you receive nothing for June 16-30 and your first annuity payment isn't until August 1 for the month of July. By moving the date to May 31 instead, your annuity would begin June 1 and arrive a full month sooner. The practical cost of a poorly chosen date is often a full month of pension plus a longer wait for your first check.

Can I lose annual leave by picking the wrong retirement date?

Yes. Annual and sick leave are credited only at the end of a pay period, so retiring in the middle of a pay period forfeits that period's accrual. More significantly, if you retire after the leave year rolls over, any unused annual leave above the 240-hour carryover cap is lost rather than paid out. Timing your retirement for the end of the final pay period of the leave year lets you cash out the maximum annual leave, including use-or-lose hours, as a lump sum. Retiring after the January 2027 pay raise takes effect also increases the dollar value of that lump-sum payout.

When will I get my first annuity check?

OPM aims to process retirements within about 30 days, but it commonly takes longer, especially during peak retirement periods at the end of the year. During this time OPM issues interim annuity payments that typically cover only 40 to 90 percent of your full benefit while your record is verified, with the remainder trued up later. Retiring at the end of the month shortens the gap to roughly 4 to 5 weeks before your first payment, versus 7 to 8 weeks if you retire early in the month. Your annual leave lump sum is usually paid within a few weeks of separation, separate from the annuity.

Sources
  1. Government Executive, setting your 2026 retirement date
  2. FedWeek, picking a retirement date under CSRS & FERS
  3. FEBA, best dates to retire in 2026
  4. Interior Business Center, best days to retire (2026)
  5. OPM, FERS information