Top Per Diem Questions Answered for Government Travelers
Top Per Diem Questions Answered for Government Travelers
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Per diem can be confusing—especially for first-time Temporary Duty (TDY) travelers. Whether you’re a government employee or a military member, questions often come up: How does per diem actually work? What documentation do you need? And how can you avoid common mistakes that delay reimbursement? We’ve compiled the most frequently asked per diem questions—with clear, straightforward answers—to help you stay prepared and stress-free on your next assignment.
What does per diem cover?
Per diem is divided into many parts depending on your type of TDY. For example, the Department of State’s (DOS) Home Transfer Allowance (HSTA) consists of (5) components: Misc Expense, Wardrobe, Predeparture Subsistence Expense (PDSE)/ “Subsistence Expense Portion,” Lease Penalty, and Pet Shipment/Quarantine. TDY Rentals only utilizes the Predeparture Subsistence Expense (PDSE), or what’s known as Temporary Quarters Subsistence Expenses (TQSE) to find your temporary lodging and supplemental rental items. All TDY types receive Meals and Incidentals (M&IE). While lodging covers housing such as hotels or furnished apartments, M&IE covers meals and small daily costs, like tips. Lodging requires receipts, while M&IE is reimbursed as a flat allowance without receipts.
Do I need receipts for per diem?
Receipts are required for lodging and any single expense above the agency’s threshold (commonly $75). You do not need receipts for daily M&IE, but you must reduce claims if meals are provided by your agency, conference, or host. For example, if you are hospitalized for the delivery of a baby while on medevac TDY, you will be authorized lodging only and no MI&E since the hospital will provide meals during your stay.
How are per diem rates set?
Within the Continental United States (CONUS), the General Services Administration (GSA) publishes per diem rates for every U.S. city and county. Rates change annually and may be higher in large cities or during peak travel seasons. Always check the GSA per diem table before booking housing. Outside the Continental United States (OCONUS), including Alaska, Hawaii, and U.S. territories, the Department of Defense (DoD) sets the rates, while the Department of State (DOS) sets foreign per diem rates.
What happens if lodging costs more than per diem?
If your lodging costs exceed the authorized per diem rate, you are responsible for the difference. Agencies will only reimburse up to the published per diem rate, even if your actual costs are higher.
Can per diem be averaged across the duration of an entire trip?
No. Each day must be claimed at the exact authorized per diem rate or lower. Averaging per diem is not allowed and will result in compliance issues or voucher rejection. Find out more at our summary video on how to avoid this common pitfall.
Are per diem payments taxable?
When properly documented, per diem reimbursements are non-taxable under IRS accountable plan rules. If receipts are missing or excess funds are kept, reimbursements may be treated as taxable income.
Why understanding per diem questions matters
Understanding per diem rules helps ensure faster voucher approvals, fewer out-of-pocket expenses, and a smoother TDY experience. By learning the answers to common per diem questions, you’ll stay compliant, avoid delays, and make the most of your travel allowance on every assignment.
