Federal Firefighter High-3 Salary: What Counts and What Doesn't
The high-3 average salary drives your entire FERS annuity calculation. For federal firefighters, the question of what qualifies as "basic pay" for this calculation is more complicated than it is for standard GS employees — and the answer depends on whether you're a structural or wildland firefighter.
Getting this wrong in either direction is costly. Undercount your basic pay and you're modeling a lower annuity than you'll actually receive. Overcount it — assuming hazard pay or incident premiums are included — and you'll be blindsided by a smaller check.
How the High-3 Works
Your high-3 is the highest average annual basic pay you earned over any 36 consecutive months of federal service. It doesn't have to be your final three years — it's whichever three-year window produces the highest average.
For most firefighters, the highest window is their final three years because of step increases and pay schedule adjustments. But if you took a voluntary downgrade, moved to a lower-graded position, or had significant LWOP late in your career, an earlier window might be higher.
What Counts: Structural Firefighters (GS-0081)
Structural firefighters at DoD installations work a 106-hour biweekly tour of duty. Under 5 U.S.C. § 5545b, the regular overtime hours within this standard tour are treated as basic pay for retirement purposes. This is a significant advantage — retirement deductions are automatically withheld from this overtime pay, and it rolls directly into the high-3 calculation.
Included in high-3:
- Base GS grade and step salary
- Locality pay
- Regular overtime within the 106-hour biweekly tour (§ 5545b)
Not included:
- Overtime beyond the standard tour
- Hazardous duty pay (25% differential under 5 U.S.C. § 5545(d))
- Night pay differentials
- Holiday premium pay
What Counts: Wildland Firefighters (GS/GW-0456)
Wildland firefighter pay was restructured when OPM established the GW pay schedule, effective March 23, 2025. The permanent Special Base Rates under this schedule count as basic pay for FERS purposes — retirement deductions are withheld, and these rates are included in the high-3.
Included in high-3:
- GW Special Base Rate (the permanent rate for your grade/step)
- Locality pay
Not included:
- Incident Response Premium Pay (450% of hourly rate during wildfire deployments)
- Overtime
- Hazardous duty pay (25% differential)
- Environmental differential pay
The distinction between GW Special Base Rates and Incident Response Premium Pay is the single most important line for wildland firefighters to understand. The special base rate is permanent basic pay — it's on every paycheck regardless of whether you're on a fire. The incident premium is temporary compensation tied to specific deployments, and it's excluded by statute under 5 U.S.C. § 5547.
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Common Misconceptions
"All my fire pay counts." It doesn't. The pay that shows up on your earnings statement during a deployment includes components that are explicitly excluded from basic pay. Only the portions identified as base salary and locality actually feed your retirement calculation.
"Hazard pay is part of basic pay." The 25% hazardous duty pay differential is premium pay under 5 U.S.C. § 5545(d), not basic pay. It doesn't count toward the high-3 for any federal firefighter.
"My high-3 is just my last three years." It's the highest 36 consecutive months, which is often but not always the final three years. If GW Special Base Rates gave you a significant raise partway through a year, the 36-month window starting from that raise date might produce a higher average than a window starting at the beginning of the year.
Verifying Your High-3
Request a certified annuity estimate from your agency retirement office at least a year before retirement. Compare their high-3 figure against your own calculation by pulling 36 months of pay stubs and summing only the basic pay components.
If you spot a discrepancy, the most common cause is the inclusion or exclusion of § 5545b overtime for structural firefighters or GW Special Base Rates for wildland personnel. The Federal Firefighter Retirement Guide includes a pay-component audit checklist broken out by series to help you catch these issues before they reach OPM.
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