What does TDY stand for? In the military and in federal government jobs, TDY stands for temporary duty: an assignment that sends you away from your regular duty station for a limited time, after which you return home. A soldier sent to a school for six weeks, an airman supporting an exercise overseas and a civilian auditor visiting a field office for a week are all on TDY.
The idea is close to a business trip in a private company. The difference is that TDY comes with written orders, set travel rules and allowances for lodging and meals that the government pays while you are away.
Quick facts
Stands for
Temporary dutyType
Initialism, said T D YUsed by
Army, Air Force, Space Force, many federal agenciesNavy and Marine term
TAD, temporary additional dutyOpposite
PCS, permanent change of stationPaperwork
TDY orders and a travel voucherIn texting
Sometimes short for today
What does TDY stand for in the military?
The tdy acronym is built from two words, with the Y taken from the end of "duty":
- T for temporary
- D and Y for duty
Using the first and last letters of one word is an old habit in military shorthand, which is why the letters do not match a three-word phrase. TDY covers any official trip where the member keeps the same permanent unit and home base but works somewhere else for days, weeks or a few months. Training courses, conferences, inspections, deployments for exercises and support missions can all be written up as TDY.
The government and military acronyms section lists many related terms you will find on the same paperwork.
How a TDY assignment works
- Orders are issued. They list the place, the dates, the purpose and how you will travel.
- Travel is booked. Many members use a government travel system and a government travel card for flights, rental cars and hotels.
- Allowances apply. Per diem covers lodging plus meals and incidental expenses, at rates set for each location.
- You do the work. The job at the TDY location is your duty for that period.
- You file a voucher. After returning, you submit receipts and a travel claim so the costs are settled.
An email from a supervisor: "Sgt. Lee will be TDY to the training center from the 3rd through the 21st. Please route her taskings to me." In plain words, Lee is away on official temporary duty and will come back after the 21st.
TDY vs PCS vs TAD
| Term | Stands for | What it means |
|---|---|---|
| TDY | Temporary duty | Short assignment away, then return to the same home station |
| TAD | Temporary additional duty | The Navy and Marine Corps name for the same idea |
| PCS | Permanent change of station | A move to a new home base, often with family and household goods |
The key test is where you belong when the trip ends. With TDY and TAD you come back. With PCS, the new place becomes home. A long TDY on the way to a new base, such as a school between two assignments, is sometimes called TDY en route.
TDY outside the uniform
Federal civilian employees use the same term. Travel rules for civilians follow federal travel regulations, while service members follow joint travel rules. The basics are the same: approved orders, a set purpose, lodging and meal allowances and a claim when you get back. Contractors may see TDY in their contracts when they travel to support a government client.
In everyday texting, tdy is also a lazy way to type "today," as in "meeting moved to 3 tdy." In a work message from a base or agency, though, it nearly always means temporary duty.
TDY in a sentence
- "I have a two-week TDY to the base in Georgia next month."
- "He's TDY right now, so expect slow replies."
- "Keep your hotel receipts for the TDY voucher."
- "The unit sent a team on TDY to help with the exercise."
- "My spouse is gone on so many TDYs this year that we count them on the calendar."
As the examples show, TDY works as a noun ("a TDY") and almost like an adjective or adverb ("he is TDY"). Out loud you hear three letters, and on paper you see three capitals and no dots. Use "a," giving "a TDY trip," because the letter T begins with a consonant.
Words you will see next to TDY
TDY orders sit in a crowd of other short forms. MOS is the job code that may decide which training TDY you attend. GSA, the General Services Administration, sets travel rates for civilian federal trips. MRE rations may show up if the duty is in the field instead of a hotel. You may also see "per diem" (Latin for "by the day"), "M&IE" (meals and incidental expenses) and "GTC" (government travel card).
Questions people ask
What does TDY mean in the military?
It means temporary duty, a short official assignment away from your permanent duty station. You travel on orders, receive allowances for lodging and meals, and return to your home unit when it ends.
Is TDY the same as a deployment?
Not exactly. A deployment is a movement of forces for an operation, and it is often longer and handled under different orders. Some short trips to support operations are written as TDY, but the two words are not always used the same way.
How long can a TDY last?
Many last from a few days to a few months. Very long ones are less common, and some rules change once a TDY passes a set number of days, so the orders and finance office are the best guide.
Do families go on TDY?
Usually not. TDY is for the member or employee. Moving a family is part of a PCS, a permanent change of station.
How do you pronounce TDY?
Spell it out: "T D Y." Trying to say it as one word would confuse listeners.