Per diem · IL · GSA FY2027 from October 1, 2026
Per diem rates in Illinois, FY2027
Each of Illinois' 4 GSA areas sits on a different M&IE tier in FY2027, and the DuPage County area changed its name along with its rate.
GSA FY2027 ZIP file published · rates checked · Published by Radif Partners · Rules and data
- GSA areas above the standard rate
- 4
- Highest lodging maximum
- $238
- Where
- Chicago
- Everywhere else
- $113 + $68
Federal per diem for the trip
$1,018
Chicago, IL · Sun, Oct 25 to Wed, Oct 28
| Lodging, 3 nights at the GSA maximum | $696 |
| M&IE before meal deductions | $322 |
| M&IE paid | $322 |
| Total | $1,018 |
Rates of fiscal year 2027 (October 1, 2026 to September 30, 2027). How this is calculated.
Day by day
| Day | Lodging | M&IE rate | Share | Meals off | M&IE paid |
|---|---|---|---|---|---|
| Sun, Oct 25 FY2027 | $232 | $92 | 75% | – | $69 |
| Mon, Oct 26 FY2027 | $232 | $92 | 100% | – | $92 |
| Tue, Oct 27 FY2027 | $232 | $92 | 100% | – | $92 |
| Wed, Oct 28 FY2027 | – | $92 | 75% | – | $69 |
Illinois per diem for FY2027 is set by 4 GSA areas, each on its own meals tier: Chicago (Cook and Lake counties) at $92, East St. Louis / O'Fallon / Fairview Heights (St. Clair County) at $86, Oakbrook Terrace (DuPage County) at $80 and Bolingbrook / Romeoville / Lemont (Will County) at $74. Chicago lodging peaks at $238 a night in April, May and June and falls to $148 in December, January, February and March. Every other county, Kane, Winnebago, Sangamon and Champaign included, takes the standard $113 and $68. The rates run from October 1, 2026 to September 30, 2027. Three nights in Chicago from May 10, 2027 total $1,036 at the federal maximum; from January 11, 2027 the same stay is $766. In January the DuPage rate gives $649 and an Aurora hotel in Kane County $577. The calculator starts on Chicago.
From Oak Brook Terrace to Oakbrook Terrace
The FY2026 GSA file listed DuPage County as "Oak Brook Terrace". The FY2027 file lists it as "Oakbrook Terrace", one word, and the lodging cap moved from $115 to $123. The county and the $80 M&IE did not change. The rename matters if your expense system matches areas by name: a lookup for the old spelling finds nothing in FY2027, and in the table at the bottom of this page the area shows up as new. Searching by ZIP code avoids the problem, since the ZIP file points to the county.
Chicago's winter discount is $90 a night
Cook and Lake counties share one calendar with four levels: $232 in October, November and September, $148 in December, January, February and March, $238 in April, May and June and $213 in July and August. A three-night trip in January costs $270 less than the same trip in May at the federal maximum, all of it lodging. Since FY2026 the spring top rose $4 and the winter floor $6. Lake County towns such as Waukegan, Highland Park and Gurnee fall inside the Chicago area too.
Chicago, IL: per diem for a stay
Lodging + M&IE at the federal maximum
$1,018
| Lodging: 3 × $232 | $696 |
| M&IE: 2 travel days at $69 | $138 |
| M&IE: 2 full days at $92 | $184 |
Lodging taxes on top; provided meals are deducted in the full calculator.
Kane County and downstate on the standard rate
Aurora and Elgin (Kane County) are among the largest Illinois cities in the Census file, and Kane County has no GSA area. Neither do Rockford (Winnebago), Springfield (Sangamon), Peoria or Champaign. In January the standard $113 is only $35 under the Chicago cap; in May the gap is $125. Joliet follows the Will County rate of $119.
St. Clair County: higher meals than DuPage
East St. Louis, O'Fallon and Fairview Heights share a flat $156 with $86 of M&IE, both above the DuPage figures. St. Louis itself is in Missouri, with its own rates on the Missouri page, so check which state the hotel is in. Illinois gasoline is priced in EIA's Midwest series at $4.109 a gallon (week of October 5, 2026); the mileage calculator applies the IRS rate of 76 cents to any route, and the arrival day in Chicago pays $69.00 of M&IE.
Every GSA area in Illinois: FY2027 against FY2026
| GSA area | Counties or limits | Lodging FY2027 | M&IE | Lodging FY2026 |
|---|---|---|---|---|
| Chicago | Cook / Lake | $148 to $238 | $92 | $142 to $234 |
| East St. Louis / O'Fallon / Fairview Heights | St. Clair | $156 | $86 | $150 |
| Oakbrook Terrace | DuPage | $123 | $80 | new in FY2027 |
| Bolingbrook / Romeoville / Lemont | Will | $119 | $74 | $114 |
| Rest of the state | All other counties | $113 | $68 | $110 |