The short version
In the United States, the working assumption behind estate planning is simple: it is your property, so you decide who gets it. You can leave everything to a spouse, to one child and not another, to a friend, or to a charity, and a valid will is expected to carry out your wishes. Brazil does not work that way. Brazil is a civil-law country with forced heirship, which means the law itself reserves a fixed share of your estate for a protected class of relatives, and you cannot write them out by will. That reserved share is called the legítima, and under the Brazilian Civil Code it is half of the estate.
If you are an American who dies domiciled in Brazil, or who owns Brazilian property, this rule can collide head-on with a US will. Your US document may not control the disposition of Brazilian-situs assets, and half of what is governed by Brazilian succession law may be locked to forced heirs no matter what your will says. This article explains the rule, separates it cleanly from US estate tax, which is a different question, and lays out the practical awareness an American should carry into cross-border planning. One thing up front: drafting the actual documents is a legal matter for qualified counsel in both countries. My lane here is tax and financial awareness, not legal advice.
What the law actually says (primary authority first)
Brazil codifies forced heirship in its Civil Code, the Código Civil, Lei 10.406 of 2002. Two articles do the work.
First, the law names who is protected. Under Article 1.845 of the Código Civil, the necessary heirs (herdeiros necessários) are the descendants, the ascendants, and the spouse. Descendants are children and, below them, grandchildren. Ascendants are parents and, above them, grandparents. The surviving spouse is included alongside them. This is a defined legal class, not a matter of preference, and membership in it is what triggers the reserve.
Second, the law sets the size of the reserve. Under Article 1.846 of the Código Civil, the necessary heirs are entitled, by operation of law, to half of the estate, and that half is the legítima. In plain terms, when you leave necessary heirs behind, the law walls off one half of the estate for them before your wishes are consulted. The companion provision, Article 1.789, states the same idea from the testator’s side: when there are necessary heirs, the person making a will may dispose of only one half of the estate. The other half is theirs by right.
So the structure is fixed. Half of the estate is the legítima, reserved for the necessary heirs and beyond the reach of your will. The remaining half is the disposable portion (the parte disponivel), the part you actually get to direct. You can give that disposable half to whomever you choose, including a necessary heir, a different person, or a charity. What you cannot do is reach into the reserved half and redirect it. A will that tries to leave the whole estate to one person, or to someone outside the protected class, runs straight into Article 1.846 as to any assets Brazilian succession law governs.
Now the separation that keeps this from getting confused. Forced heirship is a civil-law constraint on who inherits. It is not a tax. It is a completely different question from the US estate tax, which asks whether a transfer at death is taxable and at what exemption. For 2026, the US estate-tax basic exclusion amount is 15,000,000 dollars, raised by the 2025 law commonly called the One Big Beautiful Bill and made permanent, indexed going forward, per the IRS. That 15,000,000-dollar figure decides how much can pass before US estate tax applies. It says nothing about who is allowed to inherit. Brazil’s legítima decides who inherits a reserved half. The US exemption decides what is taxed. A reader can clear the US estate-tax question entirely, owe not a dollar of US estate tax, and still have half of their Brazilian estate locked to forced heirs. Two different doors. This article is about the disposition door, not the tax door, and the US exemption is here only so the two are not mistaken for each other.
How it works in practice
Consider an American couple who retire to Florianópolis. Over the years they buy an apartment in Brazil, open Brazilian bank and investment accounts, and keep a brokerage account and a house back in the United States. One spouse has two adult children from an earlier marriage. They each sign a US will leaving everything to the surviving spouse, and on the second death, everything to a favorite niece.
Walk the Brazilian assets through the Civil Code. The children are descendants, so they are necessary heirs under Article 1.845. The surviving spouse is a necessary heir too. That means the legítima under Article 1.846 reserves half of the Brazilian estate for the protected class, and the niece, who is not in that class, cannot take it. The US will can direct only the disposable half of what Brazilian law governs. The half reserved as legítima passes to the necessary heirs by force of law, and the wish to leave everything to the niece fails as to that half. The plan the couple thought they had signed does not match the plan Brazilian succession law will actually carry out.
A few mechanics make this sharper:
- It attaches to Brazilian-situs assets and to a Brazilian domicile. Brazilian real property and assets administered under Brazilian succession proceedings are the clearest exposure. Where a person dies domiciled matters to which law governs the succession, which is exactly why an American building a life in Brazil cannot assume US rules will travel with their Brazilian property.
- A US will does not automatically override it. Americans tend to assume one well-drafted US will settles everything everywhere. For assets that fall under Brazilian succession law, the legítima sits above the will. The document can govern the disposable half. It cannot rewrite the reserved half.
- The reserved half is split among the necessary heirs under Brazilian rules, not yours. You do not get to decide that one child takes the whole reserved half and another takes nothing. The Civil Code, not your preference, allocates within the protected class.
- It runs alongside, not instead of, Brazilian inheritance tax. Brazilian states levy their own transfer tax on inheritances, the ITCMD, separate from anything discussed here and separate from US estate tax. Forced heirship is about who inherits. The ITCMD and the US estate tax are about what is taxed. Three different questions, and a cross-border plan has to answer all three.
The throughline is that intent is not enough. In the United States, a clear will is usually the end of the inquiry. For Brazilian-situs assets, the Civil Code reserves half before intent is consulted, and no amount of careful US drafting changes that reserved half.
The numbers
Here is the disposition math under the Brazilian Civil Code, side by side, with the US estate-tax figure shown separately so the two are not blurred. The first three rows are the same civil-law rule stated three ways. The last row is the tax question, a different door.
| Question | What it governs | Figure or rule | Authority |
|---|---|---|---|
| Who is a forced (necessary) heir? | Who is protected by the reserve | Descendants, ascendants, and the spouse | Código Civil (Lei 10.406/2002) Art. 1.845 |
| What share is reserved (the legítima)? | The portion you cannot redirect by will | One half of the estate | Código Civil (Lei 10.406/2002) Art. 1.846 |
| What can you freely dispose of by will? | The portion your will actually controls | The other half (the parte disponivel) | Código Civil (Lei 10.406/2002) Art. 1.789 |
| US estate tax (a separate question) | What is taxed at death, not who inherits | 2026 basic exclusion 15,000,000 USD, permanent | IRS, 2026 inflation adjustments (One Big Beautiful Bill) |
Read the table top to bottom and the point lands. Three rows describe one civil-law constraint: half is reserved, half is disposable, and a defined class of relatives holds the reserved half. The fourth row is a different subject entirely. The reserve is not a tax, and the tax is not a reserve.
What this means for you
A few practical points, in the awareness lane, not the legal-advice lane.
First, separate disposition from tax in your own head, the same way the table does. The question who is allowed to inherit my Brazilian assets is answered by Brazilian civil law, and for half the estate the answer may be the necessary heirs regardless of your will. The question will my estate owe US estate tax is answered by the 15,000,000-dollar exemption and is usually no for most people. Solving one does not solve the other. A plan that only optimized the tax can still deliver an inheritance result you never intended.
Second, do not assume your US will is sufficient for Brazilian assets. This is the single most common and most expensive assumption. A US will is built for a system where your wishes control. Brazilian-situs property answers to a system where a reserved half does not. If you own a Brazilian apartment, hold meaningful Brazilian accounts, or expect to die domiciled in Brazil, the gap between what your US will says and what Brazilian succession law will do is exactly the thing to get examined before it becomes your heirs’ problem.
Third, treat this as a coordination project across two countries, not a single document. Cross-border estate planning is about making the US side and the Brazilian side fit together so they do not contradict each other, so a foreign probate does not surprise the family, and so the reserved-half rule is planned around rather than discovered after death. How that coordination is actually built, whether through Brazilian-side instruments, the structure and situs of assets, or other tools, is a legal question. The awareness that the gap exists, and that it has a real dollar consequence, is the tax-and-financial point.
Fourth, know the limits of this article plainly. Drafting wills, choosing Brazilian-law instruments, and deciding how a specific asset is titled and where it sits are legal matters for qualified counsel admitted in both the United States and Brazil. I am a CPA and a Certified Fraud Examiner, not your lawyer, and nothing here is legal advice. What I can do is the tax-and-financial-readiness side, surface where a cross-border estate is exposed, flag the disposition-versus-tax confusion, and make sure the US tax picture is straight, then coordinate with the counsel who drafts the documents.
Related reading
Companion pieces in The American Expat Tax Lifecycle, Brazil country track and the Endgame cluster:
- Cross-Border Estate Planning When You Live in Brazil: Coordinating Two Legal Systems, the endgame companion to this piece, which takes the coordination problem head-on.
- The 15 Million Dollar Exemption Is Permanent: What the 2025 Law Means for Americans Abroad, which covers the US estate-tax door this article deliberately keeps separate.
- Citizen or Nonresident Alien at Death: The 15 Million Exemption vs the 60,000 Dollar Trap, on how US estate tax treats US-situs assets very differently depending on status.
- Retiring to Brazil: The Totalization Agreement That Makes Social Security Work, the front-door planning piece for the same reader.
For the underlying authorities, see the inline links above to the Brazilian Civil Code, Article 1.845 (who the necessary heirs are), Article 1.846 (the reserved half, the legítima), and Article 1.789 (the disposable half), and the IRS 2026 figure for the separate US estate-tax exemption, all listed in the Sources block.
How Sheepdog Tax can help
I am a CPA and Certified Fraud Examiner, and this is a veteran-owned practice. The worry I hear most from Americans putting down roots in Brazil is about US taxes following them across the border. The quieter and more expensive surprise is on the estate side, where a US will and a Brazilian forced-heirship rule can point in opposite directions on the same property, and the family only finds out after a death.
A good first step is a free cross-border tax and estate-readiness review: a plain look at where you live or plan to retire, what you own on each side of the border, and where your US documents and the local rules may not line up, including the disposition-versus-tax distinction this article walks through. I do not draft wills and I do not give legal advice, that is counsel’s role in both countries. What I offer is an honest reading of your tax-and-financial readiness and a clear handoff to the legal drafting that has to happen alongside it. Every situation is different, and I do not promise a particular result. To start, reach me at noah@sheepdogtax.com.
Sources (primary authority first, then secondary commentary)
- Código Civil, Lei No 10.406, de 10 de janeiro de 2002, Art. 1.845 (herdeiros necessários: descendentes, ascendentes e cônjuge). Presidência da República, Planalto. https://www.planalto.gov.br/ccivil_03/leis/2002/l10406compilada.htm
- Código Civil, Lei No 10.406, de 10 de janeiro de 2002, Art. 1.846 (a legítima: metade dos bens da herança pertence de pleno direito aos herdeiros necessários). Presidência da República, Planalto. https://www.planalto.gov.br/ccivil_03/leis/2002/l10406compilada.htm
- Código Civil, Lei No 10.406, de 10 de janeiro de 2002, Art. 1.789 (havendo herdeiros necessários, o testador so podera dispor da metade da herança). Presidência da República, Planalto. https://www.planalto.gov.br/ccivil_03/leis/2002/l10406compilada.htm
- IRS, IRS releases tax inflation adjustments for tax year 2026, including amendments from the One, Big, Beautiful Bill (2026 estate-tax basic exclusion of 15,000,000 USD). https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill
- 26 U.S.C. 2010, Unified credit against estate tax (basic exclusion amount, as amended for 2026 and made permanent). Legal Information Institute, Cornell Law School. https://www.law.cornell.edu/uscode/text/26/2010
Prepared by Noah Green, CPA, CFE.