2027 GSA Per Diem and IRS Mileage Rates: Travel Reimbursement Guide (Updated 9/2027)

Updated September 8, 2026.

FY2027 per diem update: GSA’s FY2027 rates apply to federal travel beginning October 1, 2026. The standard lodging limit increases from $110 to $113 per night, while the standard meals and incidental expenses (M&IE) rate remains $68 per day. These dates differ from the IRS mileage-rate periods discussed below.

The General Services Administration (GSA) publishes federal travel and per diem guidance, while the Internal Revenue Service (IRS) sets optional standard mileage rates used for business, medical, and certain moving expenses. Organizations that reimburse travel, meals, and mileage need to account for both sets of rates.

For finance teams managing business per diem and mileage manually, rate changes require more than replacing a number in a spreadsheet. The applicable amount can depend on the destination, travel date, trip length, partial-day rules, and the organization’s reimbursement policy.

Use the DATABASICS GSA per diem calculator to estimate lodging and M&IE amounts by destination and travel date.

FY2027 GSA Per Diem Rates

GSA’s FY2027 standard CONUS rates apply to federal travel performed from October 1, 2026, through September 30, 2027. The standard rate applies to locations without a separately listed non-standard rate.

Source: GSA Per Diem Bulletin FTR 27-01.

Check the destination and travel dates in the GSA rate lookup. Non-standard locations may have different lodging and M&IE amounts, and some lodging rates vary by season.

GSA rates govern federal travel reimbursement. Private employers that use GSA rates should confirm their own reimbursement policy, tax treatment, and any contract, grant, or client requirements before changing rates.

IRS Standard Mileage Rates for 2026

The IRS increased the optional standard mileage rate for business use to 76 cents per mile for eligible mileage beginning July 1, 2026.

The applicable mileage rate depends on when the eligible transportation expense was incurred. Retain both 2026 business rates so mileage from January through June is not recalculated at the July rate.

For example, 1,000 eligible business miles incurred before July 1 would be reimbursed at $725 using the earlier rate. The same mileage incurred beginning July 1 would be reimbursed at $760 using the revised rate.

Estimate trip costs with the free DATABASICS Global Mileage Reimbursement Calculator.

For more detail, read our 2026 IRS mileage rate guide.

Source: IRS Internal Revenue Bulletin 2026-29, Announcement 2026-11.

Per Diem Rules Finance Teams Need to Document

Per diem calculations can depend on the destination, travel dates, trip duration, and the organization’s policy. Before applying a new rate schedule, document:

• Which rate source and reimbursement method the organization uses.
• When the new rates become effective under the organization’s policy.
• How first and last travel days are handled.
• How provided meals are deducted from the M&IE allowance.
• How single-day and multi-city travel are handled.
• How exceptions and manual overrides are reviewed and documented.

For federal travel, the first and last day of a trip generally receive 75% of the applicable M&IE rate. Private employers should confirm the partial-day rule used in their own policy.

Trips That Cross September 30 and October 1

If an organization’s policy adopts FY2027 GSA rates on October 1, a trip that crosses the date may contain two rate schedules. For example, a trip from September 28 through October 3 may use the FY2026 schedule for the September travel dates and the FY2027 schedule for travel on or after October 1.

The report’s submission date should not change the rate applicable to an earlier travel date. Finance teams should test this scenario in their expense workflow before the new rate period begins.

Why Per Diem Errors Happen

Per diem discrepancies can result from incorrect dates, locations, or policy settings. Common examples include:

• Applying a full-day M&IE amount to the first or last travel day.
• Using the standard rate when the destination has a non-standard rate.
• Applying a rate from the wrong fiscal year.
• Failing to deduct meals provided during travel.
• Using a manual override without the required explanation or approval.

When rules live only in spreadsheets, PDFs, or policy documents, employees and approvers must interpret them during each trip. Building approved rules into the expense workflow can make the process more consistent.

How DATABASICS Supports Per Diem Management

DATABASICS Expense supports configurable per diem rates and rules within the expense reporting workflow, including location-based rates, trip-duration rules, and first- and last-day adjustments.

• Configured federal per diem rates and policy rules.
• First- and last-day travel adjustments.
• M&IE calculations based on travel location, dates, and policy.
• Policy checks and approval routing.
• Project, grant, and cost-center allocation.
• Expense and approval records that support reporting and reconciliation.

These requirements also appear in DATABASICS customer stories. The CALIBRE Systems case study lists GSA per diem calculations and validations alongside project cost accounting and approval workflows. Creative Associates International identified government per diem setup and a currency feed among its requirements for a combined time, expense, and leave management system.

When rates change, finance teams should test the applicable dates, locations, partial-day rules, and approval behavior in their configured workflow.

2027 Per Diem Update Checklist

• Confirm the rate source, reimbursement method, and effective date.
• Assign responsibility for updating and approving rates.
• Preserve historical rates for earlier travel.
• Test a trip spanning September 30 and October 1.
• Check partial-day calculations and provided-meal deductions.
• Review exceptions and manual overrides.
• Notify employees and approvers about the policy change.
• Confirm that expense, payroll, and ERP integrations preserve the travel date and reimbursement calculation.

Mileage and Per Diem Shouldn’t Be Separate Systems

Mileage reimbursement and per diem often appear on the same trip. Managing them in separate processes can create duplicate entries, missed policy rules, and additional reconciliation work.

With DATABASICS, mileage and per diem can move through the same expense workflow. Employees have one place to submit travel expenses, managers receive consistent approval information, and finance teams receive records for accounting and reporting.

Final Thought

GSA per diem rates and IRS mileage rules follow different schedules. Finance teams need to preserve the applicable rate for each travel date, document their policy choices, and test rate changes before they affect reimbursement.

Book a DATABASICS demo to discuss how mileage and per diem management can fit within one expense reporting process.

This article is for informational purposes only and does not constitute legal, financial, tax, or compliance advice. Consult a qualified advisor about your organization’s specific situation.