Frequently asked questions
Answers that explain the limit as well as the rule.
What is per diem?
Per diem is the framework used to reimburse allowable lodging, meals, and incidental expenses during qualifying official travel. The lodging portion is generally actual cost up to a ceiling; M&IE is an allowance subject to travel-day and furnished-meal rules.
Does MyPerDiem use official data?
CONUS rate searches request the public GSA Per Diem API. The site identifies its manual assumptions and links the GSA, DTMO, Department of State, and JTR sources used for guidance. It is not an official government system.
Why can nearby ZIP codes return different lodging rates?
GSA publishes non-standard areas by locality and county, and a metropolitan area can border a standard-rate area. Seasonal lodging rates can also vary by month. Use the temporary-duty location from the authorization and verify the returned locality.
Are the first and last days always 75%?
Qualifying first and last travel days generally use 75% M&IE. Same-day travel, travel of 12 hours or less, multiple TDY locations, and other circumstances can require different treatment. The calculator does not know the trip’s hours or every itinerary segment.
Do I deduct a complimentary hotel breakfast?
GSA states that complimentary hotel meals and common-carrier meals do not affect per diem. Government-furnished meals or meals included in a registration fee may require deductions. Apply the rule for the traveler and authorization rather than assuming every free meal is deductible.
Does a 31-day trip automatically receive 75% per diem?
No. Current JTR reduced-rate provisions require an authorized reduced rate based on the circumstances. MyPerDiem does not automatically reduce rates based on duration.
Are lodging taxes included?
That depends on the location and governing rules. CONUS lodging taxes may be handled as a separate reimbursable expense, while foreign-area treatment can differ. Over-cap lodging can also affect the allowable tax calculation. Enter taxes only as a planning assumption and verify them.
Why does the OCONUS calculator require manual rates?
Outside CONUS, the correct source varies between foreign and non-foreign areas, locality names can be ambiguous, currencies and effective dates matter, and an authorization can establish special conditions. Manual entry avoids pretending a generic country search decided the entitlement.
Does MyPerDiem save my itinerary or report?
Calculator math and report generation occur in the browser. A CONUS rate search sends location and rate-period inputs to this server so it can query GSA. The site does not ask for names, Social Security numbers, payment cards, orders, or voucher documents.
What should I do when the estimate differs from DTS or my orders?
Use the official authorization and travel system, identify the exact input causing the difference, consult the current JTR or agency rule, and ask the authorizing or finance office. MyPerDiem is designed to make that comparison easier, not to overrule it.