What per diem covers
Federal per diem rates have two components: lodging (hotel) and M&IE (meals and incidental expenses). The lodging portion changes by city and time of year — peak-season rates in places like NYC or San Francisco can exceed $300/night while remote locations stay near the standard $107 floor. M&IE is bracketed into six tiers nationwide ($59–$92/day) and covers food plus tips to porters, hotel staff, and the like. On the first and last day of travel, the IRS requires only 75% of the daily M&IE.
GSA, IRS, and DoD rates — which one applies
GSA rates apply to federal civilian employees traveling within the continental US (CONUS). DoD-issued JTR rates apply to military and Department of Defense civilian travel, including OCONUS (Alaska, Hawaii, territories, foreign). Private employers and self-employed individuals can use the GSA rates voluntarily under the IRS "high-low" substantiation method, which avoids needing receipts for amounts at or below the published rate. Anything above the federal rate is taxable income to the traveler.
How we calculate the total
Total per diem = (lodging rate × nights) + (M&IE rate × full travel days) + (M&IE × 0.75 × first and last day). Most calculators including ours simplify by treating every day as a full day; you should manually reduce the first and last day to 75% if you need IRS-exact substantiation. For partial-day departures and returns, the simplified method usually overstates the total by 12–18%.
Worked Examples
4-day conference in Chicago (peak)
| Lodging rate | $229/night |
| M&IE rate | $79/day |
| Trip days | 4 |
$1,232 total ($916 lodging for 4 nights + $316 M&IE for 4 days).
A typical work-trip calculation. The IRS-exact figure with first/last-day 75% adjustment would be about $1,193 — $39 less than the simplified daily total.
Week-long site visit, standard CONUS
| Lodging rate | $107/night (standard) |
| M&IE rate | $59/day (standard) |
| Trip days | 7 |
$1,162 total ($749 lodging for 7 nights + $413 M&IE for 7 days).
Most rural and small-city US travel falls into the standard rate buckets. This is the floor — you cannot reimburse below standard CONUS for federal travel.
Frequently Asked Questions
How often do per diem rates change?
GSA publishes updated CONUS rates every October 1 (the start of the federal fiscal year). Rates can change mid-year for "non-standard areas" if local lodging costs spike, but this is rare. State Department rates for foreign travel update monthly.
Is per diem taxable income?
Per diem at or below the federal published rate is non-taxable when used under an "accountable plan" — meaning the employee submitted travel dates and a business purpose, even without itemized receipts. Amounts above the federal rate are taxable wages and appear on the W-2.
Can a 1099 contractor claim per diem?
A self-employed traveler can deduct the GSA M&IE rate on Schedule C without keeping meal receipts — only travel dates and destinations are required. Lodging always requires receipts for self-employed deductions; the GSA lodging rate cannot be claimed without proof of payment.
What if my hotel costs more than the per diem rate?
For federal employees the lodging rate is a ceiling — exceptions require written justification. Private employers can choose to reimburse actual lodging costs above per diem; the excess is taxable wages unless the employer adopts an "actual expense" plan with full receipts.
Are weekends included in per diem?
Yes, if you remain at the travel location for legitimate business reasons (e.g., a Friday meeting and Monday meeting with cheaper Saturday-night airfare). The IRS allows the full M&IE for non-travel days during a continuing business trip.
Sources
Marcus has spent 12 years analyzing consumer lending, refinancing strategies, and household balance sheets. Former credit analyst at a regional bank, he focuses on translating dense Fed and CFPB data into decisions readers can act on the same day.