Americans in Ireland: The 2026 Estate Tax Rules That Could Change Your Inheritance Plan

Why The 2026 Headline Is Not The Whole Story

If you are an American living in Dublin, Cork, or Galway, the 2026 US estate tax changes and the Irish Capital Acquisitions Tax regime together define the real planning picture, and the two systems do not line up in the way most families expect.

This article explains how the One Big Beautiful Bill Act (OBBBA) changed the US estate and gift tax regime for American families in Ireland, how Ireland's Capital Acquisitions Tax (CAT) works alongside it, and, for families with assets between $1 million and $10million, where the real planning questions now sit.

What Actually Changed

The One Big Beautiful Bill Act (OBBBA),signed into law in 2025, permanently sets the federal estate, gift, and GST taxexemption at $15 million per individual for deaths and gifts occurring on orafter January 1, 2026. A married couple, using portability, can shelter $30million combined. The figure is indexed for inflation from 2027. The topfederal estate tax rate remains 40%.

For US citizens and US-domiciled individuals, OBBBA applies regardless of where the person lives. A US citizen in Dublin is taxed on worldwide assets at death, just as a US citizen in Boston is. OBBBA changed the size of the exemption, not whether it applies to Americans abroad.

What OBBBA did not change is the rest of the system: US state-level estate taxes, the $60,000 US-situs exemption for non-resident aliens, and the separate Irish CAT regime that sits alongside for families with Irish ties.

How Ireland Taxes Wealth Transfers

Ireland does not operate an estate tax in the US or UK sense. It taxes the beneficiary, not the estate, under Capital Acquisitions Tax (CAT). CAT is charged at a flat 33% on the value of inheritances and gifts received by a beneficiary, above lifetime Group thresholds that depend on the beneficiary's relationship to the disponer.

The structure matters because a single estate can produce very different CAT outcomes for different beneficiaries. The same €1 million bequest received by a child falls under Group A; received by a niece or nephew, it falls under Group B; received by an unrelated friend, it falls under Group C. Each Group has its own lifetime threshold, the cumulative amount a person can receive from anyone in that Group across their lifetime before CAT applies.

Alongside the threshold structure, Ireland operates several important reliefs. The dwelling house exemption can fully exempt a qualifying primary residence from CAT for certain beneficiaries who meet strict residence and ownership conditions. Business relief and agricultural relief provide substantial reductions for qualifying business and farming assets. Each relief has its own conditions; none apply automatically.

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Groups A, B, and C, in plain terms

Group A (children of the disponer) carries the highest lifetime threshold and is the one that most often makes an estate pass largely outside CAT. Group B (siblings, nieces and nephews, grandchildren)carries a materially lower threshold. Group C (everyone else, including unrelated partners) carries the lowest threshold, which is why unmarried cross-border couples can face an outsized CAT exposure even on modest estates. Live threshold figures are published by Revenue and updated periodically.

How the US and Irish Rules Interact

The US and Ireland have had an estate tax convention in force since 1949. It is one of the oldest US estate tax treaties and its structure reflects its age, but three features are important for American families in Ireland.

It allocates primary taxing rights using a domicile-based test: a person domiciled in the US is primarily taxed by the US on worldwide assets; Irish-situs assets remain taxable in Ireland regardless. Where both systems could apply to the same asset, the treaty allocates priority and provides a credit mechanism, tax paid in one country can be credited against the other country's tax on the same asset.

The treaty is written at the level of US estate tax and Irish CAT as they stood at the time. It does not neutralize either country's charge, and its practical operation on a modern estate is a specialist question. Both systems can apply; the treaty adjusts how they combine.

A practical point: because CAT is charged on the beneficiary and US estate tax is charged on the estate, the interaction is not symmetrical. The same $1M asset can be inside the US exemption on the estate side and still produce CAT on the recipient's side above that beneficiary's Group threshold.

What This Means for American Families with $1Mto $10M in Ireland

For most American families in Ireland in this bracket, OBBBA's $15 million federal exemption means US estate tax is unlikely to be the primary concern at death. The planning focus moves to the CAT side, and to how the estate is structured around beneficiaries.

Where the estate passes primarily to children, the Group A threshold typically absorbs a large portion of the estate, and CAT is manageable. Where beneficiaries include non-children, siblings, nieces and nephews, unmarried partners, long-term non-relative beneficiaries, CAT becomes a much more visible cost, and planning (including the dwelling house exemption where available, business and agricultural relief where applicable, and careful use of lifetime gifts against each Group threshold) moves up the priority list.

The non-US-citizen spouse layer applies in Ireland as elsewhere. In the US system, the unlimited marital deduction applies only where the surviving spouse is a US citizen; otherwise, the standard route is a Qualified Domestic Trust (QDOT). In Ireland, transfers between spouses and civil partners are generally exempt from CAT.

Irish retirement savings are a separate item worth naming. PRSAs and ARFs pass under specific rules at death, which interact with CAT and with US tax reporting of foreign retirement arrangements. For an American family in Ireland with meaningful PRSA or ARF wealth, this is a specific planning question.

What I see most often with American families in Ireland is that the estate plan is drafted for the US exemption headline and not for the Group-threshold structure of CAT. The 2026 US changes are a good prompt to revisit both sides in the same conversation.

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Irish CAT and US Estate Tax at a Glance

Illustrative comparison of the core features of the US federal estate tax regime and Ireland's Capital Acquisitions Tax regime for an American family in Ireland. The table names the mechanism rather than fixed figures; live thresholds are published by the IRS and the Irish Revenue Commissioners and change periodically.

Source: Skybound 2026

Questions To Raise With A Qualified Adviser

For a US citizen or dual national in Ireland with assets between $1 million and $10 million, a short list of questions for a qualified tax or estate professional and a cross-border financial planner includes:

• Which CAT Group does each of myintended beneficiaries fall into, and how much of their lifetime threshold havethey already used from other sources?
• If my primary residence isintended to pass to a beneficiary, is the dwelling house exemption likely to beavailable at that point?
• Are my PRSA or ARF balancesstructured in a way that is consistent with my overall estate plan and my UStax reporting of foreign retirement arrangements?
•  If my spouse is not a UScitizen, how is our estate structured to address both the US marital-deductionrules (including any QDOT) and the Irish spousal CAT exemption?
• Does the US-Ireland estate tax treaty apply to the specific assets in my estate, and is the credit mechanism being used efficiently given the estate-vs-beneficiary asymmetry?

The US exemption change is significant. For most American families in Ireland in this bracket, what it really does is move the planning conversation from the US side to the CAT side and the beneficiary-by-beneficiary structure of the estate.