Reservist Tax Deduction Glossary: Plain-Language Definitions
The terms used on this site, in plain words, with each definition based on the IRS, GSA or tax code wording where there is any, and a link to the guide that uses the term.
Entries for military or everyday words with no IRS definition say so.
Who and where
| Term | Plain meaning | Read more |
|---|---|---|
| Reserve component | Pub 463 lists the Army, Navy, Marine Corps, Air Force and Coast Guard Reserve, the Army and Air National Guard of the United States, and the Reserve Corps of the Public Health Service. | Branches covered |
| Tax home | Generally your regular place of business or post of duty, wherever your family home is, covering the whole city or general area where you work. | Who qualifies |
| Away from home | Your duties keep you away from the general area of your tax home substantially longer than an ordinary day's work, and you need sleep or rest. You need not be gone a whole day if your relief from duty is long enough for that. | Which trips count |
| Overnight | The IRS test is the need to sleep or rest while away, not a clock time; "overnight" is our shorthand. | Which trips count |
| 100-mile rule | The reservist deduction applies when you travel more than 100 miles away from home for reserve service. Travel that does not take you more than 100 miles from home does not qualify. | The 100-mile rule |
| Travel expenses | Ordinary and necessary expenses of traveling away from home for your business, profession or job. | Travel costs |
| Commuting | Travel between home and your regular workplace. It is not deductible however far you live from work. | Which trips count |
| Drill, battle assembly, annual training | Military terms, not IRS terms. The IRS text speaks of a guard or reserve meeting. | Which trips count |
Rates and per diem
| Term | Plain meaning | Read more |
|---|---|---|
| Per diem | Latin for "per day." For this deduction it means the regular federal per diem rate: the highest amount the federal government will pay its employees for lodging and M&IE in a particular area. | Per diem rates |
| GSA | The U.S. General Services Administration, which publishes the federal per diem rates: one standard rate for most of the continental U.S. and individual rates for about 300 non-standard areas. | Lodging and meals |
| CONUS and standard rate | CONUS is GSA's shorthand for the continental United States, where a standard rate applies to most of it. The standard rate covers approximately 85 percent of counties. | Lodging and meals |
| M&IE | Meals and incidental expenses. The standard meal allowance is the federal M&IE rate; incidental expenses are fees and tips given to porters, baggage carriers, hotel staff and staff on ships. | Lodging and meals |
| Federal fiscal year | The federal government's budget year, which GSA uses for its per diem tables. GSA's FY2027 table is effective October 1, 2026 through September 30, 2027, and the FY2026 table took effect October 1, 2025. | Per diem rates |
| Standard mileage rate | A set amount per mile for operating your car for business. Pub 463 says you cannot also deduct actual car expenses for that year. | Mileage rates by year |
| Actual expenses method | Deducting what the car really cost to run instead of the standard rate. Pub 463 says you cannot do both in one year. For the reservist adjustment, Pub 463 and the Form 2106 instructions limit car expenses to the standard mileage rate, so actual costs do not raise it. | Travel costs |
| 50 percent meal limit | Pub 463: whichever meal method you use, you can generally deduct only 50% of unreimbursed meal costs, but the incidental-expenses-only method is not subject to the limit. | Lodging and meals |
| First and last day | On the days you leave and return, Pub 463 lets you claim 3/4 of the standard meal allowance; federal employees get 75 percent of the M&IE rate. | Lodging and meals |
| Reimbursement | Money your unit or employer pays you for travel. Pub 3 says you can deduct unreimbursed travel expenses; Form 2106 line 7 records what you received. | Common mistakes |
| Accountable and nonaccountable plan | Pub 463 describes both. Excess money not returned within a reasonable time under an accountable plan is treated as paid under a nonaccountable plan. | Records to keep |
Forms and your return
| Term | Plain meaning | Read more |
|---|---|---|
| Form 2106 | Employee Business Expenses. Only Armed Forces reservists, qualified performing artists, fee-basis officials and employees with impairment-related work expenses may use it. | Form 2106 to Schedule 1 |
| Schedule 1, line 12 | The line on Schedule 1 (Form 1040) for certain business expenses of reservists, performing artists and fee-basis government officials. | Form 2106 to Schedule 1 |
| Adjusted gross income (AGI) | Gross income minus the deductions listed in 26 U.S.C. 62(a), including the reservist deduction. | Form 2106 to Schedule 1 |
| Above-the-line deduction / adjustment | A deduction taken in determining adjusted gross income. Reservist travel expenses are one, so they are deductible whether or not you itemize. | Form 2106 to Schedule 1 |
| Standard deduction and itemized deductions | Pub 17 says you subtract either the standard deduction or itemized deductions, which are expenses listed on Schedule A. The reservist travel deduction is taken earlier, in arriving at AGI (see above). | Who qualifies |
| Miscellaneous itemized deduction | Defined in section 67(b) as itemized deductions other than a listed set. As codified in the 2024 Code, none was allowed for tax years 2018 through 2025. | Other tax breaks |
| OBBBA | The One Big Beautiful Bill Act (Public Law 119-21). Its section 70110 applies to tax years beginning after December 31, 2025; the IRS says it made the disallowance of miscellaneous itemized deductions subject to the 2% floor permanent. | FAQ |
Records and deadlines
| Term | Plain meaning | Read more |
|---|---|---|
| Substantiation | Proving your expenses. Pub 463 asks for adequate records or sufficient evidence supporting your own statement; a record generally must be written. | Records to keep |
| Contemporaneous log | A record made at the time of the trip. Pub 463 says to record the elements of an expense at or near the time it happens, and that a timely kept record has more value than a later statement. | Mileage records |
| Documentary evidence | Receipts, canceled checks or bills. Generally required, with exceptions such as an expense other than lodging under $75. | Records to keep |
| Period of limitations (statute of limitations) | Topic 305's time limits for the IRS to assess tax and for you to claim a refund. Assessment is generally 3 years from filing (longer in some cases); a refund claim is 3 years from filing or 2 years from payment, whichever is later. | Records to keep |
| Amended return (Form 1040-X) | A corrected return, generally filed within 3 years of the original or 2 years of paying the tax. The IRS says to allow 8 to 12 weeks, up to 16 in some cases. | Amending past returns |
| Filing extension | Gives you until October 15 to file without penalties; tax owed is still due by the April filing date. | Amending past returns |
| Examination (audit) | The IRS checks that income, expenses and credits are accurate. Selection does not suggest an error or dishonesty. | Records to keep |
| Burden of proof | The IRS generally carries it on a factual issue if you offered credible evidence, met the substantiation rules and kept the required records. | Records to keep |
A worked example using these terms
For example, suppose a reservist's drill site is 101 miles from home. That passes the 100-mile rule, because the distance is more than 100. The reservist stays overnight, which meets the away-from-home test, and is not reimbursed, so the trip is a candidate for the deduction. Now take the meals. On the $68 M&IE tier, the first and last day each count at 75 percent, which is $51.00 a day. If instead the reservist spent $300 on meals and used actual costs, the 50 percent meal limit would count $150 of it, the same arithmetic Pub 3 shows. Both results are carried to Form 2106 and the total lands on Schedule 1, line 12, as an adjustment to income. The figures are the page's sample numbers, not a claim about any one return.
Related guides
- Which Reserve Components Qualify - the branches behind the term reserve component
- Lodging, Meals and the Per Diem Cap - per diem, M&IE and the cap
- Standard Mileage Rates by Year - each rate by date range
- Reservist travel deduction FAQ - short sourced answers
- Records to Keep - substantiation in practice
- All guides - the full guide list, sorted by task
Sources
- IRS Publication 463
- IRS Publication 3
- IRS Publication 17
- IRS Publication 556
- IRS Tax Topic 305
- Instructions for Form 2106
- Form 2106
- IRS Notice 2026-10
- IRS: File an amended return
- IRS: Extension of time to file
- GSA per diem rates
- 26 U.S.C. 62
- 26 U.S.C. 67
- Public Law 119-21
General information, not tax advice. These definitions are plain-language summaries; where the exact term matters to your return, read the IRS publication that defines it.