Best Month to Retire Calculator (Federal Employees)

To retire and begin receiving your FERS annuity immediately, you must meet a specific combination of age and years of creditable service. If you separate from service before meeting these requirements, you may be eligible for a deferred or postponed retirement, but not an immediate one. This calculator focuses on immediate retirement scenarios.

Here are the primary eligibility paths for an unreduced, immediate FERS annuity:

• Minimum Retirement Age (MRA): Your MRA is based on your birth year. For anyone born in 1970 or later, the MRA is 57.
• MRA + 10 Reduction: If you retire under the "MRA + 10" rule, your annuity is permanently reduced by 5% for each year you are under age 62. You can avoid this reduction by postponing the receipt of your annuity until you turn 62. This calculator assumes you begin receiving payments immediately. You can model different age scenarios with a general retirement age calculator.

For most private-sector employees, retiring in March versus April has little effect on their 401(k). For a FERS employee, it can make a tangible difference. The FERS system calculates your pension with precision, and timing is a key variable you control.

1. Sick Leave Conversion and Service Credit

This is the most significant factor. Your unused sick leave balance at retirement is converted into additional creditable service.

• The Rule: 2,087 hours of work equals one year of service credit. This breaks down to approximately 174 hours per month.
• The Cliff: The Office of Personnel Management (OPM) gives you credit for full months only. If you have 173 hours of sick leave, you get zero additional service. If you have 174 hours, you get one full month of service credit. There is no partial credit.

This "all or nothing" monthly calculation means that working an extra month or two could allow you to accrue enough sick leave to cross the 174-hour threshold, adding another month to your pension calculation forever. This calculator projects your sick leave accrual to show you which months you are likely to hit that next threshold.

2. High-3 Average Salary

Your FERS pension is based on your "High-3," the average of your highest 36 consecutive months of basic pay. For most federal employees, this will be their last three years of service.

While the impact is smaller than sick leave, each additional month you work—especially after a pay raise or step increase—slightly increases your 36-month average. Retiring at the end of a calendar year often captures the full effect of that year's pay raise in your High-3 calculation.

3. Hitting Eligibility Milestones

Working a few extra months can also be the difference in meeting a critical eligibility milestone. For example, an employee with 29 years and 9 months of service can reach the 30-year mark by working three more months, allowing them to retire at their MRA with an unreduced pension. The same applies to reaching the 20-year milestone to qualify for the enhanced 1.1% multiplier at age 62. A detailed pension calculator can show the lifetime value of hitting these milestones.

A unique and valuable feature of the FERS system is the Annuity Supplement. This is an additional payment for eligible retirees that bridges the income gap between their FERS retirement date and the age they become eligible for Social Security at age 62.

Who is eligible for the FERS Annuity Supplement?

You must retire with an immediate, unreduced annuity and be under age 62. This generally means you must meet one of two criteria:

• You retire at your MRA with 30 or more years of service.
• You retire at age 60 or 61 with 20 or more years of service.

The supplement stops automatically when you turn 62, regardless of when you actually decide to claim Social Security. Think of it as a temporary bonus designed to approximate the Social Security benefit you earned during your FERS service. It is also subject to an earnings test, meaning if you work and earn over a certain limit ($22,320 in 2024), your supplement will be reduced.

Understanding if you qualify for the supplement is a key part of choosing your retirement date. Retiring a few months early might disqualify you, whereas working until you meet the MRA+30 or 60+20 threshold could add thousands of dollars to your income until age 62. This can be a crucial part of your plan for tax-efficient retirement withdrawals.

The calculator determines your monthly FERS benefit by applying the official OPM formulas to your projected service and salary. Here are the core calculations it performs.

The calculator first determines your High-3 Average Salary, which is the foundation of the pension calculation.

High-3 Average Salary = (Salary at Retirement + Salary 1 Year Before + Salary 2 Years Before) / 3

Where:

• Salary at Retirement = Your projected basic pay on your retirement date, including estimated salary growth.
• Salary 1 & 2 Years Before = Your projected salary one and two years prior to retirement.

Next, it calculates your basic annual pension before any reductions.

Gross Annual Pension = High-3 Average Salary × Total Creditable Service Years × Pension Multiplier

Where:

• High-3 Average Salary = The result from the formula above.
• Total Creditable Service Years = Your FERS service time plus any months of credit from unused sick leave, converted to years.
• Pension Multiplier = Typically 1.0% (0.01). This increases to 1.1% (0.011) if you retire at age 62 or later with at least 20 years of service.

Finally, for those eligible, it estimates the FERS Annuity Supplement.

Annual Annuity Supplement = (Estimated Social Security at 62 × FERS Service Years) / 40

Where:

• Estimated Social Security at 62 = A simplified proxy for your Social Security benefit, estimated by the calculator as a percentage of your High-3 salary.
• FERS Service Years = Your years of service, not including sick leave credit.
• 40 = A standard divisor used in the simplified OPM formula.

Many federal employees aim to retire at the end of the calendar year (December 31) for several key reasons. While this is a popular strategy, it's essential to weigh the pros and cons for your situation.

Benefits of Retiring on December 31:

1. Maximize Lump-Sum Annual Leave Payout: You receive a lump-sum payment for all your unused annual leave. By retiring at the very end of the leave year, you carry over the maximum amount and get paid for it in the following tax year. This can be a significant cash infusion to start retirement.
2. Accrue a Full Year of Service: You get credit for the entire year of work, which contributes to your total service time and High-3 salary.
3. Potential for Full COLA: Your first Cost of Living Adjustment (COLA) on your FERS annuity is prorated based on how many months you were on the annuity rolls in the preceding year. A December retirement can position you for a larger first COLA compared to a mid-year retirement.

Considerations for a Mid-Year Retirement:

1. Tax Implications: Receiving a large lump-sum annual leave payment in January could push you into a higher tax bracket for that year. Spreading income out might be more beneficial. Use a tax-efficient retirement withdrawal calculator to model the impact.
2. Hitting a Sick Leave Threshold: The calculator may show that you cross a 174-hour sick leave threshold in, for example, October. Waiting until December might not add another full month of credit, meaning you could retire two months earlier with the same pension benefit.
3. Personal Timing: Life events, health, or simply being ready to leave the workforce are valid reasons to choose a different date. The financial optimization should not be the only factor.

Ultimately, the best strategy is to use this calculator to see the hard numbers for each month and then weigh them against your personal and financial goals.

What is the best day of the month to retire for a FERS employee?

For FERS employees, it is almost always best to retire at the end of a month. Your annuity begins the day after you separate from service. If you retire on the last day of the month, your annuity starts on the first day of the next month, and you will have received a full month's salary. Retiring mid-month creates a period where you are neither earning a salary nor an annuity.

How is unused sick leave calculated for FERS retirement?

OPM converts your total sick leave hours into months and days of service using a 2,087-hour work year table. The key takeaway is that credit is given for full months only. 174 hours equals one month of credit. Any hours that don't add up to a full month are discarded. This credit is added to your total service time for the annuity calculation but cannot be used to meet an eligibility requirement (e.g., reaching 30 years of service).

Who qualifies for the 1.1% FERS multiplier instead of 1%?

You qualify for the higher 1.1% pension multiplier if you meet two conditions: you must be at least age 62 at retirement, AND you must have at least 20 years of creditable service. If you meet these criteria, your pension is instantly 10% higher for life.

Is the FERS annuity supplement the same as Social Security?

No. The FERS annuity supplement is a separate payment from the government, paid out of the FERS fund, that approximates your Social Security benefit earned during your federal service. It ends at age 62. Your actual Social Security benefit is paid by the Social Security Administration and can be claimed anytime from age 62 to 70. You can use a Social Security lump sum calculator to compare claiming strategies.

Is my FERS pension taxable?

Yes, your FERS basic annuity is fully taxable at the federal level and, in most cases, at the state level. The portion of your annuity that you contributed to with after-tax dollars is not taxed, but this is typically a very small amount. Consider the tax implications when planning your retirement budget, and check the rules in the best states to retire for taxes.

Can I collect a FERS pension and work after retirement?

Yes, you can work in the private sector with no impact on your FERS basic annuity. However, if you are receiving the FERS Annuity Supplement (paid before age 62), your supplement is subject to an earnings test. If you earn above the annual limit, your supplement will be reduced or eliminated.

What happens to my FEHB (health insurance) when I retire?

To continue your Federal Employees Health Benefits (FEHB) coverage into retirement, you must meet the "5-year rule." This means you must have been continuously enrolled in any FEHB plan (not necessarily the same one) for the five years immediately preceding your retirement.

After using this calculator to identify your optimal retirement months, take the next steps in your planning process:

1. Run a comprehensive scenario with the federal retirement calculator to see how your FERS pension, TSP, and Social Security come together.
2. Use the how long will my money last calculator to stress-test your overall retirement plan against your expected expenses.
3. Explore how other accounts, like a traditional or Roth IRA, can supplement your federal benefits and provide tax diversification.

Last updated: July 2026