@makorin , assuming that you are US person ( citizen/GreenCard/Resident for Tax purposes ), I am not quite clear as to your situation-- what I get
(a) you own bank accounts in Japan -- is this all you have or are you talking about bank accounts and also other specified financial assets ( but no real-Estate ? ) ?
(b) Are you taking into consideration the FATCA -- 8938 -- threshold differences based on your filing status and tax home ?
I would de-couple the missed filings from current ( 2024 ) filing requirements. I say this because IRS already gets info on foreign bank accounts ( of US persons ) directly.
So my curative plan would be
1. file form 114 ( at FinCen.gov and on-line filing only ) starting from 2024 and walk backwards covering at least three years. I don't remember if it asks for reasons for missed filing -- just say you were unaware of the requirements ( which is true).
2. Then start amending your returns -- again starting with 2023 and walk backwards. These would be paper / by mail filings. On each of the amended returns provide the "reason for amending" as missed attaching form 8938 -- sign/date. Mail these at the address shown at IRS site.
3. File your 2024 return per usual -- e-file and include form 8938.
4. There is no reason for rush/panic -- as long as your reason is " not being aware of the requirement " and not purposefully ignoring the law, there is nothing to worry about.
I do have a question though -- considering that TurboTax asks you every year if you have foreign bank accounts / if you are required to file FBAR form, if you need to file form 8938 --- how did you happen to miss this blaring siren. I am assuming that you have been using TurboTax for the last few years -- yes ?
Here is a page from the IRS talking about what are specified foreign financial assets -- what is included and what is not .
Basic questions and answers on Form 8938 | Internal Revenue Service
Is there more I can do for you ?
pk
