I The rule
Commuting is never reimbursable. Home to your official duty station is your own cost, every day, forever. Local travel pays only what you drive beyond that.
The arithmetic, as a travel system does it
35 − 25 = 10 miles
10 × 76¢ = $7.60 one way.
Not 35 miles. Not $26.60. Ten miles.
If the alternate location is nearer than your usual workplace, the subtraction goes negative and the allowance is zero. That is the rule working correctly, not a system error.
You have lost nothing — you drove fewer miles than on an ordinary day.
Two kinds of mileage exist in a local claim: en route — between your home or duty station and one or more alternate locations — and in-and-around, meaning any other official driving once you are there. The commute deduction bites on the first.
II Where you start from
This single fact changes the answer, and most people do not know it.
| You depart from | Commute deducted? |
|---|---|
| Your residence | Yes — subtract your normal commute |
| Your official duty station | No — claim the full distance |
So going into the office first and driving out from there can produce a larger claim than going direct from home — but not always, because of the next rule.
Where you could reasonably have travelled from either starting point, reimbursement is based on the shorter of the two routes. It exists to stop a claim being inflated by choosing the longer origin, and most agency travel systems apply it automatically.
If you normally take public transport, the deduction is by cost, not distance: the system works out the allowance for the miles you drove, then subtracts your usual fare for that leg. Know what your fare is — you will be asked.
III Mileage Estimator
What Does the Trip Actually Pay?
IV The government car trap
If a government-furnished automobile was authorised and available and you drove your own anyway, the rate collapses.
| Situation | Rate per mile |
|---|---|
| No government car authorised or available | 76¢ |
| One was available, you chose your own | 23.5¢ |
| Motorcycle | 74¢ |
Roughly a third. The reduced rate covers the running cost of the drive rather than the cost of owning the car, which is the point — the government already offered you a vehicle.
Ask before you decide. On a one-off trip the difference is small; on a coverage assignment running weeks, it is the whole value of the claim.
V Local or TDY
Local travel is generally to a site 50 miles or less from both your permanent duty station and your commuting residence, within or near normal duty hours. Beyond that, it is ordinarily temporary duty travel, which brings per diem into play.
Agencies may define an official duty station radius of up to 50 miles, so the exact boundary is set by your agency’s own travel policy. Two people at different agencies, same drive, can get different answers — and both are right.
Find your agency’s travel policy before arguing about a claim. The FTR sets the frame; the supplement sets the number.
VI Long-term coverage
Mileage is payable because the alternate site is not your duty station. Which points at the thing to watch on an extended assignment.
How the payments quietly stop
That is a personnel action, and it should appear on an SF-50. It can also change your locality pay, in either direction.
So if you are covering another location for months, ask directly whether your duty station is being changed — and ask in writing. The answer affects your mileage, your locality rate, and potentially whether a future move counts as a relocation.
One last distinction worth holding. Mileage reimburses the vehicle. Whether the time counts as hours of work is a different question under different rules — ordinary home-to-work travel is not hours of work, and travel inside your duty station limits is treated as commuting. See FLSA status, which decides whether any of it is payable as overtime at all.
Before you drive
- Ask whether a government vehicle is authorised and available.
- Know your normal one-way commute in miles, or your usual fare.
- Work out whether leaving from home or the office pays more.
- Expect the lesser of the two routes to be used.
- Accept zero if the alternate site is closer than your office.
- Find your agency’s travel supplement, not just the FTR.
- Claim tolls and parking separately — they are not in the rate.
- On a long assignment, ask in writing whether your duty station is changing.
Questions
The miles beyond your normal commute, not the whole journey. If you drove from home and your usual commute is 25 miles, you claim 35 minus 25, so 10 miles each way at the current rate of 76 cents a mile, which is $7.60 one way. The deduction applies because you would have driven those 25 miles anyway. Had you started the day at your official duty station and driven to the alternate site from there, no deduction applies and you claim the full distance.
You get nothing, and that is the intended result rather than an error. The calculation subtracts your normal commuting distance from the distance actually driven, so where the alternate site is nearer than your usual workplace the figure is negative and no allowance is payable. Travel systems will simply return zero. You have not lost anything, because you drove fewer miles than on an ordinary day.
Distance, principally. Local travel is generally travel to a location fifty miles or less from both your permanent duty station and your commuting residence, performed within or close to normal duty hours. Beyond fifty miles the trip is ordinarily temporary duty travel, which brings per diem into play. Agencies may define an official duty station radius of up to fifty miles for this purpose, so the exact boundary is set by your agency's own travel policy rather than being identical everywhere.
Where you could reasonably have travelled to the alternate site either from home or from your official duty station, reimbursement is based on the shorter of the two routes. It stops a claim being inflated by choosing the longer starting point, and it is applied automatically by most agency travel systems. It is worth knowing before you plan your day, because starting from the office does not always produce the larger claim.
By cost rather than by distance. Where you normally use public transport, the system calculates the mileage allowance for the miles you actually drove and then subtracts the cost of your normal commute. So if your usual fare is $5.00 each way and you drove 20 miles to an alternate site, the allowance is 20 miles at the current rate less $5.00 for that leg. Keep a note of your usual fare, because you will be asked for it.
Enormously. If a government-furnished automobile was authorised and available and you chose to drive your own anyway, the rate drops to 23.5 cents a mile rather than 76 cents, which is roughly a third. The reduced rate is meant to cover the running cost of the drive rather than the cost of owning a car. Ask whether a government vehicle is available before you decide, because the difference on a regular assignment is substantial.
Watch for the official duty station changing. Mileage is payable because the alternate site is not your duty station, so if an extended detail causes your agency to designate that site as your official duty station, travel to it becomes ordinary commuting and the payments stop. The change is a personnel action and should appear on an SF-50. If you are covering another location for months, ask directly whether your duty station is being changed, and ask in writing.
That is a separate question with a different answer, and the two are often confused. Mileage reimburses the cost of the vehicle; whether the time counts as hours of work is governed by the pay rules rather than the travel rules. Time spent in ordinary home-to-work travel is not hours of work, and travel within the limits of your official duty station is generally treated as normal commuting. Where travel does take you outside those limits, the time you would normally have spent commuting is deducted from the hours counted.