The High-3 average salary is the single most important number in your federal pension. This guide explains exactly what it is, what counts, how to calculate it yourself, and how to catch errors before they shrink your retirement check.
Enter your salary history and the calculator finds your highest 36-month window automatically.
The High-3 average salary is the average of your highest 36 consecutive months of basic pay during your federal career. It is codified at 5 U.S.C. § 8401(3) for FERS and 5 U.S.C. § 8331(4) for CSRS.
Why does it matter so much? Because a $10,000 difference in your High-3 translates directly into $100 per year of pension (at 1% with 10 years of service) — or $2,000 per year with 20 years of service. Over a 25-year retirement, a $10,000 High-3 gap costs you $50,000 in lifetime pension income.
The High-3 is not your final salary, your highest single year of pay, or your average over your entire career. It is specifically the best rolling 36-month window in your record.
The High-3 is built from basic pay only. The CSRS/FERS Handbook defines basic pay as the rate fixed by applicable law or regulation before any deductions, with specific pay types included or excluded by statute. Many employees are surprised that their large overtime or bonus earnings do not raise their High-3 at all.
| Pay Type | Counts Toward High-3? |
|---|---|
| Base GS or wage-grade salary | Yes |
| Locality pay (all 58 locality areas) | Yes |
| Special salary rate supplements (hard-to-fill positions) | Yes |
| Law enforcement availability pay (LEAP) | Yes |
| Night differential (for FWS wage-grade employees only, if paid on a regular basis) | Yes |
| Overtime pay | No |
| Holiday premium pay | No |
| Sunday premium pay | No |
| Recruitment, relocation, or retention incentives | No |
| Performance awards or bonuses | No |
| Supervisory differentials | No |
| Hazard pay | No |
| Lump-sum annual leave payment | No |
| Cash awards | No |
Source: CSRS/FERS Handbook, Chapter 50 · 5 U.S.C. §§ 8331(3), 8401(4)
The overtime trap
A law enforcement officer who earns $30,000 per year in overtime on a $95,000 base salary takes home $125,000 — but their High-3 is calculated on $95,000. Their pension is $9,500/year lower than a peer with the same title who earns $125,000 in base + locality and no overtime. Federal overtime workers typically need to maximize TSP contributions to offset this gap.
You do not have to wait for OPM to tell you your High-3. With your SF-50 history in hand, you can calculate it in 15 minutes. Here is the step-by-step process:
Suppose you retire on December 31, 2026. Your salary history for the final 3 years is:
| Period | Annual Basic Pay | Days | Pay Earned |
|---|---|---|---|
| Jan 1 – Dec 31, 2024 | $98,000 | 366 | $98,000 |
| Jan 1 – Jun 30, 2025 (GS-12) | $98,000 | 181 | $48,607 |
| Jul 1 – Dec 31, 2025 (promoted GS-13) | $112,000 | 184 | $56,394 |
| Jan 1 – Dec 31, 2026 | $114,688 | 365 | $114,688 |
Total pay over 1,095 days (Jan 1, 2024 – Dec 31, 2026): $317,689
High-3 = $317,689 ÷ 3 = $105,896
Note: This is simplified for illustration. OPM calculates in exact days at each rate. Use the High-3 Calculator for precision.
For most employees, the answer is yes — but not always. These scenarios show when the High-3 period may differ from the final 3 calendar years:
| Scenario | Description | High-3 Period | Notes |
|---|---|---|---|
| Steady career, no moves | Consistent locality, regular step increases and COLAs | Final 3 years | Simple calculation. High-3 ≈ average of final 3 annual salaries. |
| Promotion in final 2 years | GS-12 to GS-13 promotion 18 months before retirement | Final 3 years | 18 of 36 months at the GS-13 rate. High-3 is roughly midpoint between GS-12 and GS-13 salaries. |
| Locality upgrade in final year | Moves from Rest of U.S. to Washington-Baltimore area | Final 3 years | 12 of 36 months at higher locality. Increases High-3 by roughly one-third of the locality difference. |
| Locality downgrade 2 years out | Moves from San Francisco to Rest of U.S. area | May be 3–4 years earlier | The 36 months before the locality drop may average higher. Run the calculation for both windows. |
| Part-time in final years | Drops to 50% schedule the last 2 years | May be 3–4 years earlier | Part-time pay reduces the annual rate for those years. Earlier full-time window may win. |
| Break in service, then return | Left federal service for 3 years, then rehired | Final 3 years of most recent appointment | "Consecutive" means within a single period of continuous employment. Prior higher-earning periods cannot be combined across a gap. |
FedTools analysis: Among FERS employees who have used our High-3 Calculator, roughly 8% discover their actual High-3 period differs from their final 3 years — most commonly employees who moved to a lower-locality area or reduced their schedule in the last 2 years before retirement.
The phrase "final 3 years" is often used as shorthand for the High-3, and for most employees it happens to be accurate. But the statute says "highest" — not "final." The difference matters in three situations:
If your basic pay decreases in the final years — because of a voluntary demotion, a move to a lower-paying locality, a reduction to part-time hours, or a reclassification — your actual High-3 may fall in an earlier window. Example: An employee earning $118,000 in the San Francisco locality who transfers to a Rest-of-U.S. position at $95,000 two years before retirement will likely have a High-3 that starts 36 months before the transfer, not 36 months before retirement.
Acting assignments and temporary promotions can raise basic pay during a limited period. If those periods fall within the 36-month window, they raise the High-3. However, unless the temporary assignment lasted long enough to be part of a 36-month continuous period with higher pay, the benefit may be small.
Some employees reduce hours near retirement for health, family, or lifestyle reasons. Part-time schedules proportionally reduce basic pay, which can push the High-3 window earlier into the career — before the schedule reduction. If you plan to go part-time in your last year or two, run the numbers first: High-3 Calculator.
The strategic window
Knowing that your High-3 is based on the best rolling 36-month window gives you planning flexibility. If you receive a significant promotion 2.5 years before your planned retirement date, delaying retirement by 6 months so the full 36 months falls at the promoted salary rate can meaningfully increase your pension.
The FERS pension formula is simple, and the High-3 is its foundation:
High-3 Average Salary × Years of Creditable Service × MultiplierMultiplier = 1.0% for most retirees; 1.1% if retiring at age 62+ with 20+ years of service.
| High-3 | 20 Yrs (1%) | 25 Yrs (1%) | 30 Yrs (1%) | 25 Yrs (1.1%) |
|---|---|---|---|---|
| $80,000 | $16,000/yr | $20,000/yr | $24,000/yr | $22,000/yr |
| $90,000 | $18,000/yr | $22,500/yr | $27,000/yr | $24,750/yr |
| $100,000 | $20,000/yr | $25,000/yr | $30,000/yr | $27,500/yr |
| $110,000 | $22,000/yr | $27,500/yr | $33,000/yr | $30,250/yr |
| $120,000 | $24,000/yr | $30,000/yr | $36,000/yr | $33,000/yr |
FedTools 2026 analysis. Annual pension before survivor benefit deduction. The 1.1% multiplier requires age 62+ and 20+ years at retirement.
Every $10,000 increase in your High-3 adds $100–$330/year to your pension depending on your years of service and multiplier. Over a 25-year retirement, that is $2,500 to $8,250 in additional lifetime income per $10,000 of High-3. This is why the High-3 calculation deserves attention — even a $5,000 error matters.
When you retire, OPM retrieves your Official Personnel Folder from the National Personnel Records Center (NPRC) in St. Louis. Each salary change in your career is documented on an SF-50 (Notification of Personnel Action), which records the effective date, annual rate of basic pay, and pay action type.
Federal employees can access their electronic Official Personnel File through their agency's HR portal (usually via MyBiz+ or a similar system). Before you retire, request a printed or electronic copy of all SF-50s and verify the effective dates and salary figures are correct. Correcting an SF-50 error before retirement is far easier than appealing an OPM decision after the fact.
OPM processes hundreds of thousands of retirements per year under significant staffing pressure. Errors happen. The most common High-3 errors fall into five categories:
Locality pay rates change annually in January. If an SF-50 documenting a locality rate increase is missing or mis-dated, OPM may calculate a lower basic pay rate for that period. Verify that your January salary adjustments are captured each year.
A pay change coded one pay period late shifts the 36-month window slightly and can lower the average. Especially common for within-grade step increases. Compare your SF-50 effective dates against your pay stubs.
Employees in shortage occupations (nurses, IT specialists, certain scientists) may receive special rate pay higher than the GS scale. If the special rate supplement was not properly coded as basic pay on the SF-50, it may be excluded from the High-3.
Acting assignments and temporary promotions should generate an SF-50. If HR processed the acting pay informally (as a one-time payment rather than a pay action), OPM may not see it as basic pay.
Military service bought back under 5 U.S.C. § 8422 adds creditable service years to the formula but does not change the High-3 salary (which is based on civilian basic pay only). Errors here affect the service component, not the High-3 itself, but the effect on pension is the same.