FERS Disability Retirement Calculator

What This Calculator Does and Why Federal Employees Need It

If a medical condition has made it impossible for you to continue working in your federal position, FERS disability retirement may be your most important financial lifeline. This free FERS disability retirement calculator helps you estimate what your monthly benefit would look like — broken down by Phase 1 (the first 12 months) and Phase 2 (after the first year until age 62).

Understanding your expected benefit amount ahead of time helps you plan your finances, evaluate your SSDI coordination, and decide whether to apply. Federal disability retirement rules are complex, and going in blind can lead to costly mistakes. According to the U.S. Office of Personnel Management, FERS disability annuities are calculated differently depending on your phase, your Social Security status, and whether the formula or your regular annuity yields a higher amount.

How to Use This Calculator

Step-by-Step Instructions

1. Enter your High-3 average salary — this is the average of your three highest consecutive years of base pay.
2. Enter your total years of creditable federal service at the time of disability.
3. Input your age at the time of disability.
4. Select the disability phase you want to estimate: 60% applies in the first 12 months; 40% applies after that.
5. Enter your estimated monthly SSDI benefit if you receive or expect to receive Social Security Disability Insurance — enter 0 if not applicable.
6. Indicate whether you are eligible for the FERS Supplement based on your age.
7. Click Calculate to see your estimated Phase 1 and Phase 2 monthly benefit with the SSDI offset applied.
8. Use Reset to clear all fields and run a new scenario.

The Formula Explained

Breaking Down the Formula

FERS disability retirement uses a two-part formula. In the first 12 months, your gross benefit equals 60 percent of your High-3 average salary. After the first year, it drops to 40 percent until you reach age 62. At 62, OPM recalculates your benefit as if you had worked to that age, using your actual years of service plus the disability years.

There is an important rule: OPM always uses the greater of the disability formula or your regular FERS annuity. So if your regular computed annuity (1% × service × High-3) is higher than the disability percentage, OPM uses the regular annuity figure instead. The SSDI offset then reduces the FERS disability benefit — by 100 percent of SSDI in year one, and 60 percent of SSDI after that.

Example Calculation with Real Numbers

A federal employee has a High-3 salary of $80,000 and 12 years of service and becomes disabled at age 48. Their Phase 1 gross benefit is 60% × $80,000 ÷ 12 = $4,000/month. Their regular FERS annuity would be 1% × 12 × $80,000 ÷ 12 = $800/month. OPM uses the higher figure of $4,000. If they receive $1,500/month in SSDI, the Phase 1 net is $4,000 − $1,500 = $2,500/month. In Phase 2 the gross drops to 40% = $2,667/month, and the SSDI offset becomes 60% of $1,500 = $900, leaving a net of $1,767/month.

When Would You Use This

Real Life Use Cases

Federal employees who develop serious or chronic medical conditions — injuries, cancer, neurological conditions, or severe mental health disorders — use this calculator to understand what income replacement they can count on before submitting their application to OPM. It is also useful for HR specialists and union representatives advising employees on their options.

If you are weighing disability retirement against other options, you may also want to review the FERS survivor benefit election calculator to understand how your decision affects your spouse’s future benefits. You can also compare disability retirement with voluntary early retirement using the lump sum vs monthly pension calculator.

Specific Example Scenario

A 52-year-old postal worker with 20 years of service and a High-3 of $70,000 is diagnosed with a condition that prevents them from performing their duties. They want to know whether disability retirement would cover their monthly expenses of $3,200. Running this calculator quickly shows them their estimated net monthly benefit in both phases so they can decide whether to apply or explore other accommodations first.

Tips for Getting Accurate Results

Use Your Official High-3 Figure from OPM Records

Do not estimate your High-3 salary from memory. Log into your Employee Personal Page or contact your agency HR to get the precise average of your three highest consecutive years of base pay. Using the wrong figure will produce an inaccurate estimate and could lead to financial planning mistakes.

Understand How SSDI Interacts with Your FERS Benefit

Many federal employees are surprised to learn that receiving SSDI reduces their FERS disability annuity dollar for dollar in the first year. Not accounting for this offset is a very common planning error. The Social Security Administration’s disability page explains how SSDI eligibility is determined and how to estimate your benefit amount.

Account for Federal and State Tax Withholding

FERS disability annuities are subject to federal income tax. Depending on your state, they may also be subject to state income tax. Your take-home pay will be lower than your gross annuity amount. When planning your monthly budget, factor in estimated tax withholding so you are not caught short after the benefit begins. You can also explore the FEHB cost calculator to account for health benefit premiums that continue in retirement.

Frequently Asked Questions

What qualifies me for FERS disability retirement?

You must have at least 18 months of creditable federal civilian service. You must have a medical condition that prevents you from performing the essential functions of your current position. Your agency must also be unable to accommodate your condition or reassign you to a suitable vacancy.

How long does the FERS disability retirement application take?

OPM disability retirement applications typically take six months to a year or more to process. You may receive interim payments while your case is pending. It is important to continue working or use sick and annual leave while your application is under review if at all possible.

What happens to my FERS benefit at age 62?

At age 62, OPM recalculates your annuity as if you had continued working through the disability period. The new benefit equals 1.1 percent times your actual service years plus your disability years, multiplied by your High-3 salary. This often results in a higher monthly benefit than Phase 2.

Can I work while receiving FERS disability retirement?

You can work in the private sector while receiving FERS disability annuity, but your earnings are subject to an income test called the 80 percent rule. If your combined earnings and annuity exceed 80 percent of your former position’s current pay, your annuity may be reduced or terminated.

Is my FERS disability annuity taxable?

Yes, FERS disability retirement annuities are generally taxable as ordinary income at the federal level. Some states also tax federal retirement income. Your FERS contributions were made with after-tax dollars, so a small portion of each payment may be excluded from income using the Simplified Method.

Does FERS disability retirement affect my Social Security retirement benefit?

No. Your future Social Security retirement benefit is calculated independently based on your lifetime earnings record. Receiving FERS disability retirement does not reduce or eliminate any Social Security retirement benefit you may be entitled to at full retirement age.

What is the difference between FERS disability and workers’ compensation?

Workers’ compensation through the Federal Employees’ Compensation Act (FECA) covers injuries or illnesses that happen because of your job. FERS disability retirement covers conditions that prevent you from working regardless of cause. You generally cannot receive both FECA wage loss benefits and a FERS annuity at the same time — you must choose one.

Can my annuity be terminated after it starts?

OPM reviews FERS disability cases periodically, typically before age 60. If OPM determines you have recovered or your earnings exceed the 80 percent threshold, your annuity may be reduced or stopped. Keeping your medical records current and responding promptly to any OPM review requests protects your benefit.

Conclusion

FERS disability retirement is a critical benefit for federal employees who are no longer able to work due to a medical condition, but its two-phase structure and SSDI offset make it genuinely complex to estimate without the right tool. This FERS disability retirement calculator gives you a realistic starting point for both your Phase 1 and Phase 2 monthly income so you can plan with confidence.

Use this estimate alongside guidance from your agency HR office and, if possible, a federal retirement specialist. For additional federal benefits planning, check out the TSP early withdrawal tax calculator to understand how tapping your Thrift Savings Plan might affect your overall financial picture during the application waiting period.