What are Per Diem Rates and How Are They Set?

Per Diem Rates and How They are Set
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Per diem (from the Latin "by day") is a daily allowance for two specific travel expenses. The U.S. per diem rate includes two components: for lodging, and for meals and incidentals. The IRS says per diem is the highest allowable rate paid by the U.S. government to federal employees who are traveling away from home. Even though the rate table was originally designed for federal employees, the IRS uses it for private employers who want to provide employees with a daily budget for travel. 

If you use per diems for employee travel, anything you pay employees over the per diem rate is taxable to the employee.  

How Per Diem Rates are Determined

In the U.S. the General Services Administration (GSA) sets the per diem rate for each U.S. city and state and for foreign travel.

The per diem rates change every year, usually on October 1st. The Department of Defense and other federal agencies use the GSA per diem rate table. You can check the current per diem rates by going to this General Services Administration web page: https://www.gsa.gov/travel/plan-book/per-diem-rates

The per diem rates are important for employers to follow because reimbursements to employees in excess of the allowable per diem rates are taxable to employees as income. Employers must have an accountable plan for  employee reimbursement expenses in order to comply with IRS regulations regarding per diem expenses.

How to read the per diem rate table

GSA Per Diem Rate Table (CONUS refers to the continental U.S.; OCONUS refers to outside the continental U.S.) This information is primarily for U.S. government employees, but it can be used by private employers who want to use the per diem rates. 

The per diem table now is searchable. You can search by state and city or by zip code. You will see a breakdown of lodging rates by month and the per diem for meals and incidentals at the right. Some months may be different. Notice that this is the "maximum lodging rate per month, including taxes." Rates paid in excess of the maximum are taxable to employees as income. 

Be sure to use the correct table; the CONUS for the continental US and the OCONUS for outside the continental U.S. You can't use per diems for international travel. 

Per Diem Rates and Taxes

The IRS says that per diem reimbursements are non-taxable even if they exceed actual expenses but not if they exceed the federal rate. For example, if an employee is in Tampa for a conference in May 2016, that employee can turn in the per diem of $106, plus $54 for meals and incidentals. 

If you want to use per diems for employees, you must use them for the entire calendar year, but you can reimburse actual expenses or use meals and incidentals for specific locations. 

You can also use just the meals and incidentals if you pay lodging directly, provide lodging in-kind, reimburse actual lodging expenses. You may also use per diems for meals and incidentals for day trips where there are no lodging expenses. 

More Details, Restrictions, and Qualifications from the IRS

As usual with the IRS, there are many more details you need to know about if you want to use per diems for employee travel. Learn more about Per Diem Rates in​ IRS Publication 463: Travel, Entertainment, Gift and Car Expenses.