UNITED STATES - REPUBLIC OF KOREA INCOME TAX CONVENTION
ARTICLE 24 에 의하여
"Social security payments 한국국민연금은 and other public pensions paid by one of the Contracting States to an individual who is a resident of the other Contracting State
(or in the case of such payments by Korea, to an individual who is a citizen of the United States)
shall be taxable only in the first-mentioned Contracting State. "
한국에서만 과세 대상이며 . . .
https://www.irs.gov/pub/irs-trty/korea.pdf
https://www.irs.gov/businesses/tax-treaties-can-affect-your-income-tax
"The saving clause preserves the right of the United States to tax its citizens and residents (subject to certain exceptions) on their worldwide income, as provided under U.S. law, as if there were no treaty.
If there is no exception to the saving clause for the relevant Pension/Annuity article and paragraph, then as a U.S. citizen or resident your distribution would be taxable in the United States."
"In the US tax treaty with South Korea,
the saving clause does not apply to the social security benefits article,
which states that only the source State can tax the payment.
Therefore, Korea has the right to tax, but the US does not."
담당 CPA/EA 와 자세한 상담하시기 권합니다.