He Spent Montana’s Fire Season on Overtime. Social Security Counted Pay His Federal Pension Left Out.

Picture a federal wildland firefighter spending a punishing Montana fire season on assignment. Long rolls, night work and overtime make some paychecks look nothing like the quieter months of the year. He knows the extra work is putting substantially more money in his pocket, and it seems reasonable to assume that a bigger paycheck is also building a bigger federal pension. Not necessarily.

The Federal Employees Retirement System (FERS) and Social Security sit side by side in his retirement package, but they do not use identical definitions of pay. Overtime that may never enter his FERS high-three can still be covered wages on his Social Security earnings record. For someone whose livelihood swings sharply with fire season, that distinction can turn an exhausting summer into a surprisingly productive Social Security year.

FERS Looks for Basic Pay

A FERS pension starts with the worker’s highest average basic pay during any three consecutive years. The Office of Personnel Management specifically says the high-three generally excludes overtime and bonuses. Firefighters covered by the special retirement provisions receive an enhanced pension formula, but the high-three still starts with retirement-creditable basic pay.

There is an important wrinkle for today’s wildland firefighter. Beginning in 2025, the federal government implemented new special base rates for qualifying wildland firefighters. Those higher rates are basic pay, so they can improve the eventual pension calculation. Fire-incident premium pay, by contrast, is premium compensation rather than retirement-creditable basic pay. So the season is not invisible to his pension. The higher permanent base rate can matter. The mountain of additional overtime layered onto it generally does not raise the high-three dollar for dollar.

Social Security Reads the Same Paycheck Differently

FERS employees also participate in Social Security, with payroll deductions funding both systems. Social Security generally counts wages subject to Social Security tax as covered earnings. That means overtime can matter on the Social Security side even when it is excluded from the federal pension calculation. Social Security calculates retirement benefits using the worker’s highest 35 years of indexed earnings. If a heavy fire season produces covered earnings high enough to replace a weaker year in those 35, it can improve the eventual benefit.

There is a ceiling, however. Only earnings up to Social Security’s annual taxable maximum receive credit. Once a firefighter has already reached that limit for the year, another overtime shift may increase his paycheck without increasing the earnings Social Security records for retirement purposes. That is the number worth checking before assuming every extra hour is buying a larger future benefit.

The Firefighter Already Has a Different FERS Advantage

Federal firefighters who qualify for special retirement coverage have another piece working in their favor. Under FERS, the first 20 years of qualifying firefighter service are generally calculated at 1.7% of the high-three for each year, compared with the standard 1% formula that applies in many ordinary FERS retirements. Service beyond those first 20 years is generally calculated at 1%.

The point is not that FERS somehow shortchanges his overtime. It is that the pension rewards the career through one formula while Social Security can reward high covered-earnings years through another. A particularly strong fire season may therefore be doing useful retirement work in a place he was not looking.

Put the Two Records Side by Side

Before deciding whether all those overtime hours “counted,” he needs two different documents:

1. Check the year-by-year earnings record in his Social Security account and compare a major fire season with weaker years in his work history.
2. Get a federal retirement estimate and identify the basic pay actually being used in the high-three rather than using total W-2 compensation as a shortcut.
3. If the year’s earnings are already near Social Security’s taxable maximum, check whether additional overtime can still increase the covered earnings recorded for that year.

The overtime check did not vanish from retirement just because FERS left part of it outside the high-three. After a season spent chasing fire across Montana, some of those hardest-earned dollars may be building the retirement check he was not watching.