The United States offers broad testamentary freedom, but inheritance law varies dramatically from state to state. For blended families, this patchwork of rules creates unique challenges — from community property states where your spouse automatically owns half your assets, to elective share states where a disinherited spouse can claim a portion of your estate. Understanding these rules is the first step to protecting everyone in your family.

How inheritance law works in the United States

Inheritance law in the US is primarily a state matter. There is no single federal inheritance law. Each of the 50 states has its own rules governing wills, intestacy, spousal rights and trust law.

However, several broad principles apply across most states:

Testamentary freedom: you can generally leave your estate to whomever you choose. There is no "forced heirship" for children (with the limited exception of Louisiana, which has a civil law tradition). Adult children have no automatic right to inherit.

Spousal protection: in most states, a surviving spouse cannot be completely disinherited. The mechanism varies:

• Common law states (majority): the surviving spouse has an "elective share" — typically one-third to one-half of the estate, even if the will says otherwise
• Community property states (9 states including California, Texas, Arizona): each spouse automatically owns 50% of all marital property. You can only dispose of your half in your will

No protection for unmarried partners: unmarried partners have no inheritance rights in any US state without a will or trust.

The risks for blended families in the US

Real-world scenario — The community property surprise: Michael lives in California with his second wife, Jennifer. He assumes his separate property (assets he brought into the marriage) will go to his children from his first marriage. But over 20 years of marriage, his separate property has been commingled with community funds. At his death, tracing what is "separate" and what is "community" becomes a legal battle between Jennifer and his children.

Real-world scenario — The elective share conflict: Robert, in New York, remarries Helen. He writes a will leaving most of his estate to his three children from his first marriage, with a modest bequest to Helen. Helen exercises her "elective share" right and claims one-third of the estate. Robert's children receive far less than he intended, and the family relationship is destroyed.

Real-world scenario — The forgotten beneficiary: Linda designated her first husband as beneficiary of her 401(k) twenty years ago. She has since divorced, remarried, and has a new family. At her death, her 401(k) — her largest asset — goes to her ex-husband. In many states, beneficiary designations on retirement accounts supersede the will, and divorce does not always automatically revoke them.

Who inherits under US intestacy rules

Intestacy rules vary by state, but a common pattern is:

Federal estate tax and state taxes

The US has a dual tax system for estates:

Federal estate tax

• Exemption: $13.61 million per person (2024), meaning most estates owe no federal tax
• Rate: 40% on amounts above the exemption
• Unlimited marital deduction: transfers to a US citizen spouse are completely exempt
• Portability: unused exemption can be transferred to a surviving spouse

State estate and inheritance taxes

• About 17 states and DC impose their own estate or inheritance taxes, with lower exemptions (often $1–5 million)
• Inheritance taxes (in states like Iowa, Kentucky, Maryland, Nebraska, New Jersey, Pennsylvania) tax the recipient based on their relationship to the deceased
• Stepchildren may be taxed at higher rates than biological children in states with inheritance taxes
• Unmarried partners face the highest rates in inheritance tax states

Legal solutions in the United States

A will

A will is the foundation of any estate plan. In the US, requirements vary by state but generally include being of legal age, of sound mind, and having the will signed and witnessed. A will allows you to name beneficiaries, designate guardians for minor children, and specify your wishes.

Revocable living trust

A revocable living trust is the cornerstone of blended family estate planning in America. You transfer your assets into the trust during your lifetime and name a trustee to manage them. Key advantages:

• Avoids probate (saving time and public disclosure)
• Can include provisions for your spouse's lifetime use, with remainder to your children
• Can include stepchildren as beneficiaries
• Cannot be contested as easily as a will

QTIP trust (Qualified Terminable Interest Property)

The QTIP trust is specifically designed for blended families. Your surviving spouse receives all income from the trust during their lifetime (and qualifies for the marital deduction), but cannot change the ultimate beneficiaries. On their death, the remaining assets pass to your chosen beneficiaries — typically your children. This prevents sideways disinheritance while providing for your spouse.

Prenuptial and postnuptial agreements

These agreements can define how assets will be treated at death, waive elective share rights, and clarify separate vs. marital property. They are especially important in blended families where each partner brings significant assets or children from prior relationships.

Life insurance

Life insurance held in an irrevocable life insurance trust (ILIT) can provide tax-free proceeds to any beneficiary — including stepchildren and unmarried partners — without forming part of the taxable estate.

Beneficiary designations

Retirement accounts (401(k), IRA), life insurance and payable-on-death accounts pass by beneficiary designation, not by will. In a blended family, it is critical to review and update these designations after every marriage, divorce or family change. Note: federal law (ERISA) requires that a surviving spouse be the beneficiary of a 401(k) unless they sign a written waiver.

How to prevent family conflicts

1. Create a revocable living trust with provisions for both your spouse and your children
2. Consider a QTIP trust to balance spousal income with children's inheritance
3. Review all beneficiary designations after every marriage, divorce or family change
4. Discuss a prenuptial agreement before remarrying, especially if you have children or significant assets
5. Communicate openly with your family about your estate plans
6. Work with an estate planning attorney licensed in your state

FAQ — Blended families and inheritance in the United States

Can I disinherit my adult children in the US?

In most states, yes. Unlike many European countries, US law (except Louisiana) allows you to leave nothing to adult children. However, it is advisable to mention them in your will and state your intention explicitly, to reduce the risk of a successful contest.

What is a QTIP trust and why does it matter for blended families?

A QTIP (Qualified Terminable Interest Property) trust provides income to your surviving spouse during their lifetime, while preserving the underlying assets for your chosen beneficiaries after the spouse's death. It prevents sideways disinheritance and qualifies for the unlimited marital deduction for estate tax purposes.

Do beneficiary designations really override my will?

Yes. Assets with beneficiary designations — including 401(k)s, IRAs, life insurance and payable-on-death bank accounts — pass directly to the named beneficiary, regardless of what your will says. This is one of the most common estate planning mistakes in blended families.

What happens if I die without a will in the US?

Each state has its own intestacy rules. Generally, your spouse receives a share (often one-third to one-half), your biological and adopted children share the remainder, and stepchildren and unmarried partners receive nothing.

In the United States, estate planning for blended families requires navigating state-specific rules, federal tax provisions, and multiple legal tools. The good news is that the American system offers enormous flexibility — but only if you plan ahead. MyLastWill.io helps you organise your thoughts and document your wishes before meeting with your estate planning attorney.

This article is for informational purposes only and does not constitute personalised legal advice. Estate planning laws vary by state. Consult an attorney licensed in your state for advice tailored to your situation.