Best Time to Retire from Federal Service

The exact date you retire affects your first annuity check, how much unused annual leave you get paid out, whether your FERS pension is based on a higher salary, and whether you can tap your TSP before 59½. This guide covers the four factors that actually move the needle — and what most retirement planning articles get wrong about FERS timing.

The four factors that matter

1. Month-end timing — Your FERS annuity starts the 1st of the month after your separation date. Retiring mid-month costs you salary days with no gain. Retire on the last workday of the month.
2. Annual leave payout — If you're carrying above-cap leave that would be forfeited at the end of the leave year, retiring before forfeiture preserves thousands of dollars.
3. January GS pay raise — If a step increase or General Schedule locality pay raise is coming within 6 months, waiting can permanently increase your pension for life.
4. TSP Rule of 55 calendar year — To access TSP penalty-free under the Rule of 55 (IRC § 72(t)(2)(A)(v)), you must separate from service in the calendar year you turn 55 (or 50 for LEO/FF/ATC). This is a hard clock — missing the year means waiting until 59½.

Factor 1: Retire on the last workday of the month

FERS annuity payments are monthly, starting on the 1st of the month following the month you separate.¹ This has an important implication: it doesn't matter whether you retire on the 1st or the 31st of a given month — the annuity starts on the same date.

Retiring October 31 versus October 1 means a full extra month of salary — often $7,000 to $20,000+ depending on your GS grade — with identical annuity start dates. This is the simplest optimization and costs nothing to implement.

Practical note: Most federal employees retire on the last day of a month or the last business day before a holiday. HR processes the separation regardless of weekends, so the annuity timing isn't affected by the calendar falling awkwardly. Confirm with your agency HR department if you're retiring around a federal holiday period.

OPM processing and interim pay: No matter when you retire, OPM typically takes 60–100 days to finalize your annuity.² During that period you receive interim pay — roughly 60–80% of your estimated annuity, without FEHB deductions, without state tax withholding, and without TSP contributions. The final annuity is then retroactive to your retirement date. OPM's backlog peaks in December and January (the most popular retirement months due to annual leave timing), which can push final processing to the longer end of the range. If minimizing the interim-pay period matters to you, a spring or summer retirement date typically processes faster.

Factor 2: Annual leave payout timing

When you retire from federal service, you receive a lump-sum payment for all your accrued unused annual leave — with no cap.³ The carryover cap (240 hours for most employees, 360 for SES, 720 for overseas assignments) only applies if you're continuing to work into a new leave year. If you're still employed when the leave year turns over, any leave above the cap is forfeited.

The timing trap: If you retire on January 15 — two weeks after the leave year turned over — you've already forfeited any above-cap hours. Had you retired on December 31, you would have been paid for everything.

The federal leave year ends the last day of the last complete pay period before January 1. In most years this falls between December 27 and January 3. Check your agency leave and earnings statement for the exact date, or ask your HR office.

The lump-sum payout formula: hours × (annual salary ÷ 2,087). The full tax treatment — 22% federal supplemental withholding, no TSP contribution, no FERS deduction — is covered in the annual leave lump-sum guide.

Factor 3: The January pay raise effect on your pension

Your FERS pension is based on your High-3 average salary — the average of your three consecutive highest-paid years. A GS step increase or General Schedule pay adjustment that takes effect in January permanently raises your pension, compounded over decades.

How much does waiting matter? Example: GS-13 step 8 in the Washington-Baltimore area earning $133,000. A within-grade increase to step 9 adds $2,600/year in base pay. At a 28-year FERS pension factor, that's $728 more per year in annuity — every year, for life. If you live 25 years in retirement, the present value of that increase is roughly $10,000–$14,000.

Rule of thumb: If a step increase or annual pay adjustment is within 6 months, run the math. Waiting 6 months for a raise that permanently increases your annuity by $800/year adds up quickly. If you're more than 12 months out from any raise, the calculus shifts toward other timing factors.

Your High-3 doesn't require three full calendar years at the higher salary — it's the highest average over any three consecutive years including partial years. But because the calculation is an average, the longer you earn the higher salary, the more it raises your High-3.

Factor 4: TSP Rule of 55 — the calendar-year constraint

The Rule of 55 (IRC § 72(t)(2)(A)(v)) lets you take distributions from your TSP without the 10% early withdrawal penalty if you separate from federal service in the calendar year you turn 55 (or age 50 for special category employees — LEO, firefighters, ATC).⁴

This is a calendar-year rule, not a birthday rule. You don't need to be 55 on your retirement date. You need to separate in the calendar year you turn 55. If you were born in August 1971, you turn 55 in August 2026. You can retire January 1, 2026 and still qualify — because you separated in the calendar year you turn 55.

Why this matters: if you're 54 and were planning a January retirement, waiting until January of the year you turn 55 (instead of January of the year you turn 54) gives you immediate, penalty-free TSP access for the rest of your life. Retiring at 54 means you must either leave TSP funds untouched, use a 72(t) SEPP arrangement, or pay the 10% penalty until 59½.

There is one critical trap: if you roll your TSP to an IRA after separation, you lose the Rule of 55 benefit for that money permanently. The Rule of 55 applies only to TSP accounts (or 401(k)/403(b) accounts from the employer you separated from in that calendar year). IRA distributions before 59½ require SEPP or face the penalty.

See the TSP stay-vs-rollover decision guide for the full Rule of 55 analysis.

What doesn't affect FERS retirement date optimization

FERS COLA timing: A common misconception (based on CSRS planning advice) is that retiring in December gives you "a full year of COLA" sooner. This is not how FERS COLA works. FERS retirees receive no cost-of-living adjustments until they reach age 62.⁵ COLA timing is irrelevant for FERS retirement date decisions. (FERS disability retirees and surviving spouses receive COLA at any age — different rules apply to them.)

FERS Supplement start date: The FERS Special Retirement Supplement begins immediately for eligible employees (MRA+30 or age 60+20 retirement). It is not affected by which month or day you retire within a given year. See the FERS supplement guide for full eligibility details.

FEHB continuation: Health insurance continues into retirement without interruption as long as you meet the 5-year eligibility requirement. No timing optimization needed here.

Putting it together: the decision matrix

Interactive FERS retirement timing optimizer

Enter your details to see an analysis of your planned retirement date.

Special scenarios

You're turning 55 this year but your planned date is December

You're fine — any separation date within the calendar year you turn 55 qualifies for Rule of 55. Whether you retire in January or December of that year, the rule applies. The only scenario where timing within the qualifying year matters is if you're trying to balance the Rule of 55 against the leave year (December retirement captures both).

You have a promotion coming but it requires staying another 6–12 months

Calculate the pension impact. A promotion from GS-13 step 5 to GS-14 step 1 in a COLA-heavy locality might add $12,000–$18,000 to your annual salary. At a 28-year pension factor (1.0%), that's $3,360–$5,040 more per year in annuity — every year, for life. Six months of additional service to capture that raise is almost always financially worth it.

You're in MRA+10 territory and considering postponing

If you're retiring under MRA+10 (leaving with 10–29 years of service) and considering postponing your annuity start to avoid the 5%/year penalty, the timing rules change significantly. Postponement means your FEHB coverage is suspended during the deferral period. The MRA+10 retirement guide has the full penalty calculator and break-even analysis.

Involuntary separation (RIF, VERA)

If you're being separated involuntarily, you may not fully control the retirement date. But the Rule of 55 still applies to RIF separations — and the calendar-year constraint still matters. If your RIF is scheduled to take effect January 2 but you turn 55 in the same calendar year, separating on December 31 of the prior year means you miss it by one year. Verify the separation date carefully. See the RIF/separation guide and VERA/VSIP guide.

Building your retirement date shortlist

For most FERS employees, the optimal retirement date emerges from a simple process:

1. Identify the calendar year you want to retire — usually driven by service years and/or MRA.
2. Check whether that year is your Rule of 55 qualifying year. If not, and you're within one year, weigh the trade-off.
3. Identify any pay raises (step increases or GS adjustment) within 6 months. If yes, target the month after the raise takes effect.
4. Check your annual leave balance relative to your carryover cap. If you're above cap or close, lean toward December.
5. Given the above, pick the last workday of the target month.

For most people this produces two or three candidate dates: a December option (best for leave preservation, worst for OPM processing), a spring/summer option (faster OPM, simpler leave math), and possibly a January option if a pay raise just took effect. A financial advisor who specializes in federal employees can help model the exact financial impact of each date against your specific pension formula, TSP balance, and Social Security claiming strategy.