Illinois per diem at a glance
GSA sets its own per diem for 4 areas in Illinois. Everywhere else in the state gets the standard CONUS rate of $113 lodging and $68 M&IE.
1 of the 4 areas allow at least 50% more than the standard $113 lodging rate in their peak month.
The most a 3-night TDY can pay in Chicago is $1,036: three nights at the $238 lodging ceiling, two full days of $92 M&IE, and two travel days at 75%. At the standard rate the same trip pays up to $577.
FY2027 per diem rates in Illinois
Lodging is the nightly ceiling (your actual cost is reimbursed up to it). M&IE is a flat daily allowance you keep. "3-night TDY" is the most a 4-day trip pays at that area's peak ceiling.
| Area | County / location | Lodging | M&IE | 3-night TDY | vs FY2026 |
|---|---|---|---|---|---|
| Bolingbrook / Romeoville / Lemont | Will | $119 | $74 | $616 | +$5 |
| Chicago | Cook / Lake | $148–$238 | $92 | $1,036 | +$4 |
| East St. Louis / O'Fallon / Fairview Heights | St. Clair | $156 | $86 | $769 | +$6 |
| Oakbrook Terrace | DuPage | $123 | $80 | $649 | +$8 |
| All other locations | Standard CONUS rate | $113 | $68 | $577 | +$3 |
GSA FY2027 rates, effective October 1, 2026, through September 30, 2027. The county column is GSA's own definition of each area.
Month-by-month lodging ceilings
1 of 4 areas in Illinois change their lodging ceiling with the season. Use the month you are actually there; a trip that spans two seasons uses each night's own ceiling.
| Area | Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago | 232 | 232 | 148 | 148 | 148 | 148 | 238 | 238 | 238 | 213 | 213 | 232 |
Where the season matters most: Chicago allows $238 a night in April to June but $148 in December to March, a $450 difference over a 5-night stay. If you can influence the dates, the ceiling follows the calendar, not the hotel.
Dollars per night, FY2027 (October 2026 through September 2027). Highlighted cells are each area's peak.
What changed from FY2026
The standard CONUS lodging rate went from $110 in FY2026 to $113 in FY2027; standard M&IE stayed at $68. Of the 4 Illinois areas priced both years, peak lodging rose in 4. The largest increase is Oakbrook Terrace, up $8 a night at its peak.
Compares each area's highest monthly lodging ceiling in FY2026 and FY2027, from GSA's published rates for both years.
Meal breakdown and travel days
On the first and last day of travel you receive 75% of the M&IE rate. When the government provides a meal, that meal's amount comes off the day's M&IE; the incidentals portion is always kept.
| M&IE rate | Breakfast | Lunch | Dinner | Incidentals | Travel day (75%) |
|---|---|---|---|---|---|
| $68 standard | $16 | $19 | $28 | $5 | $51 |
| $74 | $18 | $20 | $31 | $5 | $55.50 |
| $80 | $20 | $22 | $33 | $5 | $60 |
| $86 | $22 | $23 | $36 | $5 | $64.50 |
| $92 | $23 | $26 | $38 | $5 | $69 |
Military travel notes
- TDY uses these locality rates (Joint Travel Regulations, chapter 2). Hotel taxes in CONUS are reimbursed separately, on top of the lodging ceiling.
- PCS travel days do not use locality rates. Driving pays a flat $181 a day (the standard rate) wherever you stop. See the PCS calculator.
- Work out a specific trip, including provided meals, in the per diem calculator.
Source: GSA per diem rates API, FY2027. Estimates for planning; your orders and the Defense Travel System decide what is paid.