GSA Per Diem Rates: How Federal Travel is Reimbursed
A federal employee sent to Cleveland for three days does not, contrary to popular imagination, fish receipts out of a coat pocket and beg an accountant for mercy. Instead, a number is looked up in a table, and that number — broken into a sum for the hotel and a smaller sum for everything else — becomes the reimbursement. The table is maintained by the General Services Administration, and the mechanics behind it are stranger and more deliberate than the bureaucratic blandness of the phrase "per diem" suggests.
What a Per Diem Rate Actually Is
Per diem, in federal travel parlance, is a flat daily allowance covering two distinct categories of expense incurred while on official travel away from one's permanent duty station. The first is lodging. The second is known by the slightly awkward acronym M&IE — Meals and Incidental Expenses — which folds together the cost of food and a small allowance for tips, fees, and the various unbilled frictions of being temporarily elsewhere.
Both pieces are published by GSA on a single rate page covering the continental United States. The lodging rate sets a ceiling: a traveler may be reimbursed up to that amount for the actual cost of a hotel room, with receipts. The M&IE rate works differently. It is paid as a flat allowance regardless of what the traveler actually spent on meals, on the theory that auditing every sandwich would cost more than it could possibly save.
This split — receipted ceiling for lodging, flat allowance for meals — is the central design choice of the system, and most of the program's quirks descend from it.
CONUS, OCONUS, and the Geography of the Rate Table
Federal travel divides the world into three zones, each governed by a different rate-setting authority.
CONUS stands for the Continental United States, meaning the 48 contiguous states and the District of Columbia. CONUS rates are set by GSA itself and published on the GSA Per Diem Rates page.
OCONUS — Outside the Continental United States — is everything else, and is further subdivided. Non-foreign OCONUS areas, which include Alaska, Hawaii, Puerto Rico, Guam, the U.S. Virgin Islands, and other U.S. territories, have their rates set by the Department of Defense through its Defense Travel Management Office. Foreign OCONUS rates, covering everywhere outside U.S. sovereignty, are set by the Department of State.
GSA's own per diem page links out to the DoD and State tables for these other zones, but does not set them. A traveler going from Washington to Honolulu and then on to Tokyo is, technically, drawing on rates set by three different federal entities over the course of one trip. The traveler need not know this, which is rather the point.
How a Rate is Set
The CONUS rate-setting methodology, as described by GSA, is built around lodging market data. GSA contracts for hotel rate information — average daily room rates in each surveyed market — and uses that data to establish a lodging ceiling intended to reflect what a federal traveler can reasonably expect to pay at a mid-range property during the off-peak portion of the year.
The phrase "off-peak" matters. By design, the standard lodging rate is not the average across the entire year; it leans toward the cheaper months, on the reasoning that travel during conferences, festivals, and tourist seasons is the exception rather than the rule. When a location has a genuinely seasonal market — coastal Maine in August, ski country in February — GSA may publish seasonal rates that step up and down through the calendar.
M&IE rates are set on a different basis, drawing on meal cost data and structured into tiers. A given location is assigned to one of several M&IE bands, each with a fixed total and a fixed breakdown for breakfast, lunch, dinner, and incidentals. The breakdown matters because of a separate rule: when a meal is provided to the traveler at no cost — a working lunch at a conference, say, or a hotel breakfast included in the room rate — the corresponding portion of that day's M&IE must be deducted.
The first and last days of travel are reimbursed at 75 percent of the M&IE rate, on the simple logic that a traveler departing at noon or arriving at dinnertime is not eating a full day's worth of meals on the government's account.
The Standard Rate and the Non-Standard Areas
Most CONUS counties are not individually surveyed. Instead, they fall under what GSA calls the standard CONUS rate — a single nationwide default applied to any location not specifically listed. The standard rate is deliberately modest and is intended to cover the large rural and small-town majority of American geography where hotel costs are unremarkable and stable.
Locations where costs depart meaningfully from the standard are designated Non-Standard Areas, or NSAs. These are typically larger cities, resort destinations, and other markets where lodging runs hotter than the national default. Each NSA has its own lodging rate (often seasonal) and its own M&IE tier. The GSA per diem table is, functionally, a list of NSAs plus a footnote saying "everywhere else, use the standard rate."
The mechanics of the lookup, then: a traveler or travel coordinator enters a destination by city, ZIP code, or county; the system returns either an NSA rate, the relevant seasonal NSA rate for the dates in question, or the standard CONUS rate. The lookup tool lives at gsa.gov/travel/plan-book/per-diem-rates and is the canonical reference for any CONUS trip.
A small but important wrinkle: per diem is determined by where the traveler stays overnight, not necessarily by where business is conducted. Someone working in a high-cost city but lodging in a cheaper suburb across a county line draws the suburb's rate. This produces occasional minor strangeness — a meeting in Manhattan reimbursed at a New Jersey rate — which the regulations accept as the price of having a clean rule.
The Annual Cycle
Per diem rates run on a fiscal year, not a calendar year. The federal fiscal year begins on October 1, and the new rate table takes effect that day. GSA typically publishes the upcoming year's rates in mid- to late summer, giving agencies and travel systems time to load the new figures before they go live.
Rates may be adjusted between annual cycles, but only in specific circumstances. A location experiencing a sustained and significant departure from its current rate — a sudden hotel boom, the arrival of a new industry, a natural disaster that compresses lodging supply — can be reviewed mid-year, and individual federal agencies can petition GSA for such a review. Most rates, however, simply hold steady from October through September and then change.
The standard CONUS rate, the NSA list, and the seasonal date ranges are all subject to revision each year. A city that was an NSA last year may revert to standard if its market cools; a county that was standard may be added to the NSA list if its lodging costs have climbed.
Exceptions: When the Rate is Not Enough
The per diem ceiling is the default, but federal travel regulations recognize that defaults occasionally fail. Two principal exception mechanisms exist.
The first is the actual expense allowance, sometimes called actual subsistence. When the published rate is genuinely insufficient — a major event has consumed every reasonably priced room within fifty miles, for example, or the traveler must stay at a specific designated hotel — an agency may authorize reimbursement above the standard ceiling, up to a regulatory cap (commonly 300 percent of the applicable per diem rate). This requires advance approval and documentation; it is not something a traveler invokes by booking an expensive hotel and hoping for the best.
The second is the conference lodging allowance, which permits reimbursement at the actual cost of lodging at an officially designated conference hotel, even when that cost exceeds the local per diem ceiling, subject again to limits and approvals. The logic here is that the cost of attending the conference is itself the point of the travel, and forcing attendees to lodge inconveniently far from the venue tends to defeat the purpose.
There are also reductions. A long-term temporary duty assignment — staying in one location for an extended period — can trigger a reduced flat rate, on the reasoning that someone living somewhere for several weeks tends to find an apartment, cook some of their own meals, and generally settle into something cheaper than nightly hotel life.
Where Per Diem Sits in the Larger Travel Apparatus
Per diem is one piece of a federal travel system that GSA assembles from several distinct programs. The City Pair Program negotiates discounted, fully-refundable airfares between high-volume city pairs for federal travelers. GSA SmartPay issues the charge cards on which most official travel expenses are booked. The Federal Fleet program supplies vehicles for official use, and a separate set of GSA-published rates governs reimbursement for travel in privately-owned vehicles.
Per diem provides the answer to "how much for the hotel and meals." The other programs answer "how do you get there," "what do you pay with," and "what if you drive yourself." Together they constitute the operational framework within which the Federal Travel Regulation — codified in 41 CFR — is actually carried out.
The Federal Travel Regulation itself is the binding rulebook. GSA's per diem page implements it; the rates are the numbers; the FTR is the prose explaining what to do with them. A traveler curious about edge cases — what counts as official travel, what receipts are required, how to handle interrupted trips — is ultimately reading the FTR, whether or not anyone tells them so.
A Closing Observation
Per diem is, in the end, a small bureaucratic admission that auditing reality is more expensive than approximating it. Rather than examine each meal and each receipt, the federal government settled long ago on a system of regional flat rates, updated yearly, with documented exceptions for the cases where the flat rate breaks down. The system is unglamorous, occasionally produces odd geographic artifacts, and works tolerably well for several million trips a year. There are worse fates, in government design, than tolerably well.