Must I Report My Spouse’s Income If I Am Assigned to the United States Without My Spouse?

Not necessarily. If your spouse remains in Japan, the treatment depends on their U.S. tax status, your filing approach, and any prior residency elections.

Living in Japan does not automatically eliminate U.S. obligations, and marriage does not automatically require a joint return.

1. Your Spouse Is a U.S. Citizen or Tax Resident

U.S. citizens and tax residents generally must consider worldwide income, including Japanese salary, even while living in Japan.

Filing requirements and the choice between joint and separate returns require additional review.

Reference: IRS — Taxation of U.S. Residents

2. Your Spouse Is a Nonresident Without a Residency Election

If your spouse is neither a U.S. citizen nor a tax resident, and no election treats them as a resident, their salary for work performed in Japan is ordinarily outside their U.S. federal income tax liability.

U.S.-source income or work performed in the United States may create a separate filing obligation.

Married filing separately is generally considered, although another filing status may be available if its requirements are met.

References: IRS — Taxation of Nonresident Aliens, IRS — Publication 519

3. You Elect to Treat Your Nonresident Spouse as a Resident

Eligible couples may elect resident treatment when one spouse is a U.S. citizen or resident and the other is a nonresident at year-end.

The election year requires a joint return reporting both spouses’ worldwide income for the entire year. The election generally continues until terminated or suspended, so future filing obligations should also be considered.

Reference: IRS — Nonresident Spouse