Guam

Research notes

Guam — family-office tax dossier

Last reviewed: 2026-10-15 Tax year: 2026 Reviewer: research agent (Claude), unreviewed by a tax adviser

Summary

Guam applies a 'mirror' of the US Internal Revenue Code: the same rules and rates as US federal income tax, paid to Guam instead of the IRS. Long-term gains and qualified dividends are taxed at up to 20%, other income up to 37%. There is no Guam estate, gift or wealth tax. US citizens who are bona fide Guam residents file only with Guam, but stay inside US federal estate and gift tax.

Residence and eligibility

Bona fide residence under IRC §937(a): presence test (e.g. 183 days in the territory), no tax home outside Guam, and no closer connection to the US or a foreign country. A bona fide Guam resident files only with Guam (IRS Pub. 570).

Routes:

• US citizens: free movement (US): No immigration permission needed.
• Non-US citizens: US immigration status (EU, OTHER): Guam applies US immigration law: a visa or green card is needed. A green card makes the holder a US tax resident.

US citizens: A US citizen who is a bona fide Guam resident for the whole year files only with Guam and owes no separate US federal income tax (IRS Pub. 570); the Guam mirror tax has the same rates, so the income tax burden is about the same as in the US, without US state tax. US federal estate and gift tax continues to apply to US citizens born or naturalised outside Guam (IRC §2209 exception only for citizenship acquired through the possession).

Capital gains

Capital gains are taxed under the mirrored US Code: long-term gains on assets held over one year at 0%/15%/20%, so a large gain is taxed at 20%. Short-term gains are ordinary income (top 37%).

Rate basis: Top long-term capital gains rate of the mirrored Internal Revenue Code (20%). IRS Pub. 570: Guam's tax system is 'based on the same tax laws and tax rates that apply in the United States'. The 3.8% net investment income tax is not included: IRS says it does not directly apply to bona fide territory residents and its mirrored application is a question for the territorial tax department.

Holding period rules: More than one year for long-term treatment (mirrored IRC §1222).

Professional trader: As in the US code: dealers and traders with mark-to-market elections are taxed at ordinary rates.

Foreign assets: Worldwide income; foreign taxes creditable under the mirrored foreign tax credit rules.

Confidence: medium; verification: partially_verified.

JSON: headline 0.2; listed domestic 0.2, listed foreign 0.2, private business 0.2, local real estate 0.2, foreign real estate 0.2.

Dividends

Dividends are taxed under the mirrored US Code: qualified dividends at up to 20%, non-qualified dividends at ordinary rates up to 37%.

Rate basis: Qualified dividend rate 20% under the mirrored IRC §1(h)(11) used for both domestic and foreign dividends; non-qualified dividends (e.g. from some non-treaty foreign companies) would be taxed at up to 37%. Under the mirror system 'United States' is read as 'Guam', so how dividends from US and foreign companies qualify was not confirmed.

Withholding outbound: Mirrored US rules: 30% statutory withholding on dividends paid to non-residents (US treaties do not apply as Guam treaties).

Treaty network: Guam has no income tax treaties of its own; US treaties do not extend to Guam. Source-country WHT on US/foreign dividends is relieved by the mirrored foreign tax credit.

Confidence: medium; verification: partially_verified.

JSON: domestic 0.2, foreign gross 0.2, foreign tax relief 'credit'.

Inheritance and gifts to children

Guam has no estate, inheritance or gift tax of its own; the mirror system covers income tax only. US citizens remain within the US federal estate and gift tax (added by the app); see us_citizen_notes.

Gift tax: No Guam gift tax.

Domicile rules: US citizens: federal estate and gift tax on worldwide assets unless IRC §2209 applies (citizenship acquired solely through birth or residence in a possession). Non-US citizens domiciled in Guam are treated as non-resident aliens for US estate tax (US-situs assets only).

Mirror system covers income tax only (IRS Pub. 570). IRC §2209 (opened) treats a possession resident as a non-citizen for estate tax only if citizenship came solely from the possession.

Confidence: low; verification: partially_verified.

JSON: basis 'none', children 'fully_exempt', exemption 0 USD, brackets [].

Wealth tax

No net wealth tax.

Property tax note: Guam levies a real property tax on assessed value; rate not researched. A gross receipts tax applies to businesses.

Confidence: medium; verification: partially_verified.

JSON: type 'none'.

Special regimes

None researched. Guam Economic Development Authority qualifying certificates rebate income tax for approved business investments; they do not cover a passive portfolio.

Company taxation (kept separate from personal tax)

CIT rate in JSON: 0.21. Mirrored US corporate income tax at 21%. Guam Economic Development Authority qualifying certificates can rebate most income tax for approved investments (not researched).

Cost of living notes

Not sourced in this pass (no cost_of_living block). Markers: Hagåtña (13.4757, 144.7489; Wikipedia (Hagåtña, Guam), approx.).

Open questions

• Mirrored net investment income tax (3.8%) in Guam not confirmed.
• Guam DRT primary sources not opened; relies on IRS Publication 570.
• [standard/capital_gains] Whether Guam applies a mirrored 3.8% net investment income tax (IRS Pub. 570 refers taxpayers to Guam DRT) was not confirmed.
• [standard/capital_gains] Guam Department of Revenue and Taxation primary guidance was not opened; relies on IRS Pub. 570.
• [standard/dividends] How the qualified-dividend rules apply under the mirror code to dividends from US and foreign companies was not confirmed.
• [standard/wealth_tax] Guam real property tax rates not researched.
• [standard/inheritance] No Guam statute or DRT page confirming the absence of a territorial estate or gift tax was opened; IRS Pub. 570 only describes income tax.

Sources

• IRS Publication 570 (2025): Tax Guide for Individuals With Income From U.S. Territories: https://www.irs.gov/pub/irs-pdf/p570.pdf
• 26 U.S. Code § 2209 - Certain residents of possessions considered nonresidents not citizens: https://www.law.cornell.edu/uscode/text/26/2209
• 26 U.S. Code § 937 - Residence and source rules involving possessions: https://www.law.cornell.edu/uscode/text/26/937

Change log

• 2026-10-15: initial research.