@sarakzolner , agreeing with @ErnieS0 's excellent reply to your post, and adding the following:
(a) my personal pref. fro such types of returns is CD/Download Home & Business -- windows because it keeps all the data on my machine, allows me to see the forms as filled out and I can amend the return ( if and when needed )
(b) Recognize that US does not recognize dual citizenship i.e. as a US citizen you will not be able to assert US-Japan treaty benefits , even though you work / reside in Japan ( resident / citizen of Japan )
(c) Physical Presence test is generally the best way to proceed --- does not require permission/ approval of IRS as long as you meet the requirements of Physical Presence Test
(d) Strongly suggest familiarity with Pub. 54 ---> https://www.irs.gov/pub/irs-pdf/p54.pdf
(e) US & Japan have "Totalization agreement" in place -- re: Social Security -- please be aware of this ---- https://www.ssa.gov/international/Agreement_Pamphlets/japan.htm
Of we volunteers, TurboTax employees et al are here to help you.
