The 75% First-and-Last-Day Per Diem Rule

One rule trips up almost everyone calculating per diem by hand, and it's the single most common reason a self-built spreadsheet claim comes back from finance with a query attached: meals & incidentals (M&IE) are paid at only 75% on the day you leave and the day you return — regardless of what time you actually travel, and regardless of how much of that day you genuinely spent on the road.

Why three-quarters, and not some other fraction

The federal travel rules assume you don't need a full day of meals when you're only partly away from home — you likely ate breakfast at home before you left for the airport, or you'll have dinner at home the evening you get back. Rather than trying to prorate every trip hour-by-hour, which would be a compliance nightmare for both travellers and auditors, the Federal Travel Regulation sets a flat, simple standard: 75% of the full M&IE rate applies on the first and last calendar day of official travel, full stop. GSA's own guidance is explicit that this fraction applies regardless of actual departure and return times.

What it looks like in dollars, FY2026

Note that GSA rounds the 75% figure to the nearest whole or half dollar in its published tables rather than leaving fractional cents, which is why $74 → $55.50 rather than a longer decimal. Our M&IE calculator applies the correct tier automatically once you pick a destination.

A worked example

Take a three-day trip to a city on the standard $68 M&IE rate: you fly out Monday morning, work Tuesday, and fly home Wednesday evening. The M&IE math is $51 (Monday, 75%) + $68 (Tuesday, full day) + $51 (Wednesday, 75%) = $170 in M&IE — not $204, which is what you'd get if you mistakenly paid all three days at the full rate. Lodging is calculated separately and added on top for the two nights you actually stayed (Monday and Tuesday night), since the 75% rule never touches lodging.

Does it matter what time you actually travelled?

No — and this is the part that surprises people most. Whether your flight leaves at 6am or 9pm on day one, the first day of travel is still paid at 75%. The rule is date-based, not clock-based. The one genuine exception is a same-day trip with no overnight stay at all: that single day is also paid at the 75% M&IE rate, with no lodging component, since there's only ever one "first and last day" when the trip doesn't span a night.

How this interacts with provided meals

If a conference or client provides you with a meal on your travel day, GSA expects you to deduct that specific meal's dollar value from the already-reduced 75% figure, not from the full rate — see are provided meals deducted from per diem? for the exact breakfast/lunch/dinner splits used in that calculation.

“Employees are reimbursed at 75 percent of the applicable M&IE rate for the day of departure from the permanent duty station and the day of return.”

— U.S. General Services Administration, Federal Travel Regulation guidance, gsa.gov

Why getting this wrong matters

Overstating M&IE by paying full rate on travel days is exactly the kind of error that pushes a reimbursement above the federal ceiling — which, as we cover in is per diem taxable?, turns the excess into taxable wages rather than a tax-free reimbursement. For a full walkthrough of building a trip total from scratch, see how to calculate per diem for a business trip.