DNA Tests and Estate Planning

Takeaways

• At-home DNA tests are revealing previously unknown biological relatives, who are then using these results to make legal claims on estates, even years after death.
• To protect your estate plan, be sure to clearly define whom you intend to inherit and explicitly address whether biological relatives discovered later should be included or excluded.

It’s often the smallest details in an estate plan that have the biggest impact — a short clause or a subtle word choice that ensures your wishes are followed. But something even smaller — your DNA — can undo an estate plan in the time it takes to spit into a tube.

Around one in five adult Americans has taken an at-home DNA test. That figure is only slightly lower than the roughly one in four Americans who have a will.

The risks of dying without a will or trust were always high. But direct-to-consumer genetic testing has added a new wrinkle — and new risks — to estate planning. Long-lost relatives are now surfacing with genetic “proof” to support claims that they are legal heirs.

For most families, the primary risk isn’t just a loss of assets; it’s a potential barrage of legal hurdles. These hurdles may include the court halting distributions to your intended heirs and funds being depleted from the estate to cover legal fees.

In the age of Ancestry.com and 23andMe, silence in your will is no longer a neutral choice; it’s an invitation for a laboratory result to dictate your legacy.

From Consumer Novelty to Legal Bombshell

Historically, estate planning relied on a stable, knowable family tree. Even if rumors or circumstantial evidence suggested the existence of a “secret” child, these possibilities rarely factored into estate planning because they couldn’t be proven in court.

That dynamic began to change in the early 2000s. Consumer-facing companies like 23andMe and AncestryDNA took advantage of advances in biotechnology to bring DNA testing into everyday homes, marketing it as a simple way to explore one’s ancestry.

For the first time, you could mail a saliva sample from home to unlock genetic insights once available only through laboratories. People marveled at the novelty of seeing their family trees grow in real time.

As these tests became mainstream, massive genetic databases emerged. The more people who participated, the more unexpected biological relationships surfaced. Previously unknown (or, in some cases, intentionally concealed) children, siblings, or parents were identified through algorithmic matching.

What many users initially viewed as a novelty increasingly produced life-altering revelations, ranging from “you’re one-third Swedish” to “you have a third sibling.”

Those revelations have begun to collide with inheritance law. Most estate plans, especially older ones, were drafted before consumer DNA testing existed and rely on broad definitions of “family.” Today, that broad phrasing can be used as a legal “open door” for any biological relatives to walk through.

While at-home DNA results are not always final proof, they can be enough to pause probate and trigger court-ordered testing, effectively letting lab results override your best-laid plans.

Real Inheritance Disputes Triggered by At-Home DNA Tests

Most families have at least one story about a child, sibling, or other relative who was never formally acknowledged. There might be an old letter, picture, or tale that hints at them, but it likely remains mere family folklore.

Formerly unknown biological parents, half-siblings, and other relatives are now appearing in disputes over who should inherit, sometimes after an estate has already been settled. In some cases, this has led to estates being reopened and courts taking a second look at earlier decisions.

• Massachusetts DNA inheritance lawsuit. In 2023, Carmen Thomas used a 23andMe test to discover two half-sisters whose father had died years earlier. After learning their family received roughly $28 million from a medical malpractice settlement, she sued her newfound siblings seeking a share of the award as a biological child. The claim was dismissed, however, in part because it was filed too long after the father’s death.
• Australian estate reopened via DNA testing. A man from Australia used a consumer DNA test to prove he was the biological son of someone whose multimillion-dollar estate had already been distributed. The court accepted the genetic proof, reopened the estate, and awarded him an equal share.
• Fred Eversley estate claim. Following the death of renowned sculptor Fred Eversley, a California woman filed a claim in Manhattan in 2025 asserting she was his biological daughter based on her 23andMe DNA results. Eversley’s will, finalized months before his death, left the bulk of his $39 million estate to his wife and siblings and excluded her. There is no final ruling yet, but the case is another example of how a DNA test kit can force a multimillion-dollar estate into a public legal battle over inheritance.

Planning Lessons From DNA-Driven Inheritance Disputes

While family inheritance disputes are nothing new, these cases expose new probate and planning risks from the first wave of at-home DNA legal challenges.

Families can no longer assume that far-flung relatives lack the evidence to support an inheritance claim. The proof is in the genes — and a $200 at-home testing kit.

That doesn’t mean courts will automatically accept a consumer genetic test as indisputable proof that somebody was wrongly excluded. Some use DNA testing to quickly verify paternity or reopen estates. Others require extensive evidence, especially when paternity had not been previously established.

But DNA testing does mean that wills and trusts should be reevaluated to hedge against the possibility of “accidental” heirs, posthumous paternity claims, and distribution delays.

DNA Testing Has Shifted When Heirs Appear

Biological relationships that once remained speculative or unknowable can now surface years — or decades — after a person’s death. In some cases, DNA-based claims have emerged only after probate had begun or distributions were underway, forcing courts and estate administrators to revisit issues they thought were settled.

• Estate planning lesson: Make sure your estate plan considers the possibility that previously unknown biological relatives could surface later. Being clear now can help prevent courts from having to decide what you would have wanted.

Dying Without a Will Leaves Little Room for Intent

The most disruptive outcomes tend to arise when someone dies intestate (without a will or trust). Under intestacy law, courts are often required to prioritize biological relationships, even when those relationships were unknown, unacknowledged, or inconsistent with the decedent’s expectations.

• Estate planning lesson: A simple will or trust can help ensure that your wishes are followed. Without one, state law decides who inherits — and that may not match what you would have wanted.

Avoid Vague Family Terms

Generic references to “children” or “descendants” can become fault lines when DNA evidence surfaces. What seemed clear when your plan was drafted may be disputed later.

• Estate planning lesson: Be specific when defining who counts as family in your estate documents. Name individuals, clarify legal relationships, and describe how others should be treated so your intentions are clear, even if unexpected relatives appear.

Biological and Legal Relationships Don’t Always Match

Some courts have treated biological parentage as decisive for inheritance, even in cases where legal parentage (like adoption) suggested otherwise. This means families can’t always rely on legal status alone to determine who inherits.

• Estate planning lesson: Be clear in your estate plans about whether you want inheritance rights to depend on biological relationships, legal relationships, or both. Leaving that decision up to the court’s interpretation of state law invites uncertainty.

The Real Risk Is Delay and Disruption

These cases do not point to a flood of successful inheritance claims. The more common impact is delay: probate can slow down, distributions may be paused, costs can rise, and families may face months — or even years — of uncertainty.

• Estate planning lesson: Good estate planning can’t eliminate every uncertainty. However, it can reduce the risk of delays and disputes. The goal is to make administration as smooth as possible, even if unexpected DNA claims arise.

How to “DNA-Proof” Your Estate Plan

Estate planning is as much about preparing for the unknown as it is preparing for the known. DNA testing falls into the first bucket. It adds a layer of complexity and uncertainty that, if not planned for, can disrupt an otherwise solid plan and throw an estate into chaos. Here’s how to ensure that the results of a DNA testing kit don’t rewrite your estate plan.

• Define your “class” of heirs. Instead of leaving money to “my descendants,” list people by name. (Also be specific about who should not inherit.)
• Include an “accidental heir” clause. Estate plans can state whether biological relatives discovered after administration or death are included, excluded, or subject to conditions.
• Don’t let the state decide. If you die without a will, state law decides who inherits — usually based on bloodlines. A will or trust lets you choose who gets what instead of leaving it to default rules that may not match your wishes.
• Give your executor time to review claims. Your plan can let them pause distributions, set aside assets, or get legal guidance before paying anyone — helping avoid mistakes without putting them at risk.
• Use trusts to give yourself flexibility. A trust can let distributions happen gradually or give your trustee discretion, so money isn’t paid out immediately while questions about heirs or DNA claims are resolved.
• Check that your beneficiary designations match your overall plan. Accounts like retirement plans, life insurance, and payable-on-death assets can pass outside your will or trust. Make sure they reflect the same intentions about who should inherit — including any potential heirs revealed by DNA testing.
• Update older documents. If your estate plan was created before 2015 (when at-home DNA tests became mainstream), using “default” language may mean a court could interpret in favor of a biological newcomer.

A plan looks good on paper only if it works in the real world. DNA tests can reveal relatives you didn’t know about, but clear, up-to-date estate planning can minimize disputes and ensure your intentions are respected.