How to Keep a Reservist Mileage Log
Mileage is usually the biggest line in a reservist's travel deduction, and it is the one line nobody hands you a statement for. This guide covers what a usable log holds, how the 2026 split-year rate changes the math, and a worked year with every number shown.
The rates, and the 2026 split
The IRS publishes the business standard mileage rate by year. For 2026 it lists two rows, so one rate does not cover the whole year.
| Period | Business rate (cents per mile) |
|---|---|
| 2026, July 1 to December 31 | 76 |
| 2026, January 1 to June 30 | 72.5 |
| 2025 | 70 |
| 2024 | 67 |
Drive on June 28 and you use 72.5. Drive on July 12 and you use 76. Applying the higher rate to a whole year of drills overstates the deduction, and the example below shows by how much. The same care applies to a reservist who drives mostly in the first half of the year: the newer, higher rate does not reach back to those trips.
What the rate already covers
Publication 463 says that if you use the standard mileage rate for a year, you cannot also deduct depreciation, lease payments, maintenance and repairs, gasoline, oil, insurance or registration fees. So fuel receipts do not go on top of mileage. Business-related parking fees and tolls are the exception: they can be deducted in addition to the rate, and the publication notes that parking at your regular place of work is a nondeductible commuting expense.
What a log must show
The publication's records table asks, for car expenses, for the date of each use, the destination, the business purpose, the mileage for each business use and the total miles for the year. It also lets several parts of one use, such as a round trip, share one record. A timely record has more value than a statement prepared later. You do not have to write every entry on the day it happens, because a log kept weekly that accounts for that week's use counts as timely.
| Date | From | To | Purpose | Round-trip miles |
|---|---|---|---|---|
| Jan 10 | Home | Unit armory | Drill weekend, orders on file | 284 |
| Feb 14 | Home | Unit armory | Drill weekend, orders on file | 284 |
| Jul 11 | Home | Unit armory | Drill weekend, orders on file | 284 |
A worked year
The reservist here is invented. Her armory is 142 miles from home, so each drill weekend is 284 round-trip miles and clears the 100-mile line. She drilled nine times in 2026: six before July 1 and three after.
- January 1 to June 30: 6 trips times 284 miles is 1,704 miles, times 72.5 cents, equals $1,235.40.
- July 1 to December 31: 3 trips times 284 miles is 852 miles, times 76 cents, equals $647.52.
- Total: 2,556 miles and $1,882.92. Tolls of $9 on each of the nine trips add $81 on the line for parking and tolls.
- Had she used 76 cents for everything, the figure would be $1,942.56, which is $59.64 too high.
That overstatement looks small, but it is the kind of mismatch a reviewer can see by comparing your dates to the published table. The log is what lets you show each trip belongs in the right row.
Which trips belong in the log
Keep one log for every drive to a reserve duty location, then mark which entries qualify. Publication 3 gives the test in three parts: you are a member of a reserve component, you travel more than 100 miles away from home in connection with your reserve service, and the expenses are unreimbursed. A drill that is 100 miles or less from home still belongs in your records, but its miles do not carry to the deduction, so a simple qualifies column keeps the line 1 total honest.
If your orders or your unit paid you for the mileage, that payment is a reimbursement. Publication 463 says that if you were entitled to a reimbursement and did not claim it, you cannot deduct the expense. Form 2106 gives reimbursements their own line, so record any payment next to the trip it covers.
Why each column is there
| Log column | What it proves |
|---|---|
| Date | The day of the use, which is also how you pick the right row of the rate table |
| From and to | The destination, which orders and a map can back up |
| Purpose | The business purpose, which for reserve duty is the drill or training named in your orders |
| Round-trip miles | The mileage for the use, which adds up to the total miles for the year |
| Reimbursed? | Whether any of the trip was paid back, so line 7 is not guesswork |
A routine that takes two minutes
- Before you leave for drill, note the odometer or the route distance from your map, and add the date.
- When you get home, finish the line: purpose, miles, tolls and parking.
- Once a week, glance over the log and fix anything missing, since a weekly log is considered timely.
- Clip the weekend's orders or schedule to the entry so each line has a document behind it.
Estimates do not count
Publication 463 states plainly that you cannot deduct amounts you approximate or estimate. A record is generally expected to be written, though one kept on a computer or phone counts. Round numbers on every line, such as exactly 300 miles each time, look estimated even when they are not, and the safer habit is to record the route you really drove. If you must rebuild a year after the fact, the publication allows reconstruction only where you cannot produce a record for reasons beyond your control, so reconstruction is not a plan.
Keep the log for 3 years from the date you file the return that claims the deduction. A return filed early is treated as filed on its due date.
A reservist's note
As a reservist, I find the log easiest when it lives where I already look, such as a notes app with one line added in the parking lot after the drive home. Do not trust yourself to rebuild a year from memory in April, because the dates blur and your orders will not remember the odometer. A common slip is deducting a tank of fuel on top of the mileage figure, which is exactly the double count the publication rules out, and a log that shows only miles, not fuel, makes that slip harder to make.
Common questions
Does the commute to my own unit count?
Not automatically. Commuting between home and your regular place of work is personal. Reserve travel can be different, and the separate guide on commuting versus drill travel walks through when.
What does Form 2106 ask about my records?
Page two asks whether you have evidence to support the deduction, and whether that evidence is written. It also asks for your average daily roundtrip commuting distance.
Can I keep the log digitally?
Yes. Publication 463 says a record prepared on a computer is considered adequate.
What if my unit reimbursed only part of a trip?
Record the full trip in the log and the payment beside it. On Form 2106 the payment goes on the reimbursement line, and the form subtracts it from your total expenses before it reaches the line that carries to Schedule 1.
Which rate do I use for a return on earlier years?
Use the rate for the year of the travel. The table above lists 70 cents for 2025 and 67 cents for 2024, and a year with a mid-year change has one row per period.
Related guides
- Form 2106, line by line: where the mileage total goes.
- Mileage rates by year: the full table behind the rates above.
- Commute or drill travel?: which trips belong in the log at all.
- Records to keep: the rest of the paperwork.
Sources
- IRS standard mileage rates
- IRS Publication 463, Travel, Gift, and Car Expenses
- IRS Form 2106, Employee Business Expenses (2025)