If you were in the US in 2018 on a J1 visa, you will not be able to file a 2018 US resident return as your J1 visa would make you a nonresident.
TurboTax does
not support nonresident or dual status returns.
However we have a partnership with Sprintax offering a
nonresident/dual status tax filing solution to our TurboTax customers.
Visit
the TurboTax/Sprintax site for more info or to get started.
At the point you received your O1 visa, you will be a US resident after you meet the substantial presence test. While on the J1 visa , none of your days of presence counted for the substantial presence test.
You will be considered a United States resident
for tax purposes if you meet the substantial presence test for the calendar
year. To meet this test, you must be physically present in the United States
(U.S.) on at least:
- 31 days during the current year, and
- 183 days during the
3-year period that includes the current year and the 2 years immediately
before that, counting:
- All the days you
were present in the current year, and
- 1/3 of the days you
were present in the first year before the current year, and
- 1/6 of the days you
were present in the second year before the current year.
Please see this link more information regarding US Guide for Aliens.
Publication 519
