Your FERS High-3: What Counts Toward It—and When a Longer Career Will Not Raise It

When federal employees compare retirement dates, they often focus on one question: how many more months of service will I have? The other half of the pension calculation is your High-3 average pay.

Your High-3 is important because it is the pay figure used in the FERS annuity formula. A promotion, locality-pay change, step increase, or a few additional working years can change the result—but not always in the way people expect.

What “High-3” actually means

OPM defines High-3 average pay as the highest average basic pay earned during any three consecutive years of service. It is usually the final three years, but it can be an earlier period if that period had higher basic pay. OPM also weights each pay rate by the time it was in effect, so this is not simply the average of three calendar-year salary numbers.

Basic pay generally includes the salary for your position and increases for which retirement deductions are withheld, such as qualifying shift rates. It does not generally include overtime, bonuses, or other payments that are not basic pay. For the official definition and computation rules, see OPM’s FERS computation guidance.

Why the last three years are usually—but not always—your High-3

For a steady career with regular raises, the final 36 months will usually produce the highest average. But that assumption can fail when your pay history changes.

• A recent promotion: Retiring before three full years at the higher rate can still raise your High-3, but the earlier, lower-paid months remain part of the consecutive three-year window.
• A move to a lower-paying position or locality: An earlier three-year period may be better than your final one.
• A break in service or an unusual pay history: The calculation can require a closer look at the dates and rates rather than a shortcut based on your current salary.

The practical point: do not assume “current salary × three years” is your High-3. Ask for an agency estimate or review the pay periods that make up the actual highest consecutive three-year window.

How High-3 fits into the pension formula

For most regular FERS retirements, the basic annual annuity starts with High-3 average pay multiplied by creditable service and a 1% multiplier. If you separate at age 62 or later with at least 20 years of service, the multiplier is 1.1% instead. OPM’s retirement types guide shows both formula paths.

This is why an extra year of work can help in two distinct ways: it adds service credit, and it may replace a lower-paid month in the High-3 window with a higher-paid one. Once your High-3 has effectively plateaued, however, working longer may still increase the pension through service credit without materially increasing the pay average.

A simple way to compare retirement dates

For each date you are considering, separate the question into three parts:

• Service: How many additional months of creditable service does the later date add?
• High-3: Will higher basic-pay months enter the rolling three-year period, or has the average already leveled off?
• Multiplier and reductions: Does the later date change your age-based multiplier, avoid a reduction, or affect other benefits and cash flow?

That framing prevents a common mistake: treating every extra working month as if it has the same pension value. A month can be valuable for service, for High-3, for eligibility, or for more than one of those reasons.

Questions to take to HR before you decide

• What High-3 amount is used in my current retirement estimate?
• Which dates and basic-pay rates make up that average?
• How would the estimate change at each retirement date I am considering?
• Are there service records, deposits, part-time periods, or pay details that need to be confirmed?

How to use FERSCalc for this decision

Use Calculator Setup to compare retirement dates and enter a reasonable High-3 estimate based on your agency records. Then use the results to see how pension income, taxes, TSP withdrawals, and household cash flow change across those dates.

FERSCalc is a planning tool, not an official retirement estimate. Before you submit an application, confirm the High-3 calculation, creditable service, and final annuity election with your agency HR office or OPM.