@BillyWoolfolk
(a) TurboTax is quite capable of handling your situation ( generally ). My personal favorite is Windows download "Home & Business".
(b) Generally agreeing with you and noting that { and unlike OECD model and most tax treaties ) US-Japan Tax Treaty requires / allows only the resident country to tax the pensions from public sources -- thus SSA income is taxable only by Japan. See --------- Japan - Tax treaty documents | Internal Revenue Service
Specifically and from technical explanation ----
"Article 17 (Pensions, Social Security, Annuities, and Support Payments) This article deals with the taxation of private (i.e., non-government service) pensions and annuities, social security benefits, and support payments. Paragraph 1 Paragraph 1 provides, as a general rule, that the Contracting State of residence of the beneficial owner has the exclusive right to tax pensions and other similar remuneration. The phrase “pensions and other similar remuneration” includes both periodic and lump-sum payments. The phrase “pension and other similar remuneration” is intended to encompass payments made by a pension fund, as defined in subparagraph 1(m) of Article 3 (General Definitions), or any other payment made by private retirement plans and arrangements in consideration of past employment. Pensions in respect of government service (other than social security payments, as discussed below) generally are not covered by this paragraph, but rather are covered by paragraph 2 of Article 18 (Government Service). Thus, Article 18 covers section 457, 401(a) and 403(b) plans established for government employees. If a pension in respect of government service is not covered by Article 18 solely because the service is not “in the discharge of functions of a governmental nature,” the pension is covered by this Article. Paragraph 1 also provides for exclusive residence-country taxation of social security benefits. Like the prior Convention, but unlike the U.S. Model, the Convention provides that social security payments made by one of the Contracting States to a resident of the other Contracting State will be taxable only in the other Contracting State. This provision applies to social security beneficiaries, whether they have contributed to the system as private-sector or government employees. The provision is intended to include United States Tier 1 Railroad Retirement benefits. Paragraph 2 Under paragraph 2, any annuities derived and beneficially owned by an individual who is a resident of a Contracting State is taxable only in that Contracting State. The term “annuities” means a stated sum paid periodically at stated times during the life of the individual, or during a specified or ascertainable period of time, under an obligation to make the payments in return for adequate and full consideration (other than in return for services rendered). The term “annuities” does not include any pensions or similar remuneration that is described in paragraph 1. Annuities received in consideration for services rendered would be treated as deferred compensation and generally taxable in accordance with Article 7 (Business Profits) or Article 14 (Income from Employment), not Article 17. 7
To achieve this you would have to recognize the SSA income on your US return and then under "other income" enter a negative SSA amount with a comment " US-Japan Tax Treaty 2017 , article XX ". IMO, it is the taxable portion of the SSA that needs to be excluded and not the total -- you are trying to achieve zero taxation of the SSA in the US and let Japan tax the income.
Is there more I can do for you ?
