Your options really depend on whether you are stationed/deployed in an actual Combat zone, or stationed in some non-combat posting.
1) For a combat posting, you have 180 days after returning to get your taxes done.....or, if you choose, you can get them in now, IF you have access to all your tax information .
2) For a non-combat location station, you had an automatic 2-month extension, but that has passed...or if you actually filed for a full extension before 15 April...then you have 1 week to file before that extension ends.
Read this entire article first:
https://turbotax.intuit.com/tax-tips/military/at-ease-soldier-extensions-for-military-personnel/L3RR...
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In either case,
a) if you are going to use the Online tax software, the Online tax software will fully shut down ~ 1 week after the 15 Oct due date, but you can only do an e-file those taxes thru the 15th of Oct. (probably midnight PACIFIC time...not sure what the time would be where you are....but don't push it)
b) If you cannot file by that deadline, then you will need the CD/download/desktop software and a full MAC or Windows computer to prepare and file on paper. You can buy that software for download at the Turbotax Store, or as an Amazon Download (make sure you are at the Amazon download service site)....don't use any cheap non-major US retailers or you risk viruses or malware. A US Credit Card with a US billing address is required. But again, if not done and e-filed by 15 Oct, you will have to print and mail in your tax return and documents yourself. (if e-filed by the 15th and rejected, you can fix and re-e-file for a few more days...but beyond that you must print and mail in your tax returns, along with your tax documents W-2 forms and any other tax documents that show withholding).
If not e-filed, or e-filed and rejected, Once the Online software shuts down entirely in mid-late Oct, you cannot make any changes to whatever you have entered in the Online 2018 software and you will be required to use the desktop/download software to finish up and mail in your forms.
c) IF you end up filing later than the 15 Oct deadline, you can still file when you get back to the USA. For etither situation 1 or 2 above, there would be no Federal late-filing penalty/interest if you are getting a Federal refund....but if you owe the Feds extra $$, situation 1 would not have a penalty as long as it was paper-filed within 180 days after return to the USA…….situation 2 would have a penalty/interest for late filing if you owe additional with your late tax return filing.
d) state taxes? don't know....states can be all over the place on their rules for overseas personnel, and if they tax military income at all. But many still want a tax return filed, even if they don't tax military income.
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Right now the TurboTax desktop/download editions for 2018 are here:
https://turbotax.intuit.com/personal-taxes/cd-download/
But sometime in late Oct, or Nov or Dec, that page will switch to 2019 software, and 2018 software will move to the Prior year website:
https://turbotax.intuit.com/personal-taxes/past-years-products/
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
