You can contest unequal inheritance between grandchildren, but only in narrow circumstances: you need legal standing to bring the case, and you need evidence that the will or trust is legally defective — not just that the split feels unfair. No law requires a grandparent to treat grandchildren equally, and courts will not rewrite an estate plan because one grandchild received less than another.
Before you spend money on a lawyer or blow up family relationships, work through the questions below in order. Most grandchildren who feel shortchanged stop at the first one.
Do You Have Standing to Contest
Standing is the threshold question, and it ends most grandchildren’s cases before the merits are ever reached. To contest a will, you have to be someone who would be “adversely affected” by it, meaning you would have inherited more if the will did not exist, under your state’s intestacy rules.
Intestacy laws in every state put children ahead of grandchildren. If your parent (the grandparent’s child) is still alive, your parent is the heir — you are not. The will did not cost you anything, because you would not have inherited anything without it. No standing, no contest.
The exception is when your parent died before the grandparent did. Most states then let you step into your deceased parent’s share through per stirpes distribution: the estate first divides into shares for each of the grandparent’s children, and a deceased child’s share passes down in equal portions to that child’s own children. If the will cuts you out or gives you less than that per stirpes share would, you are adversely affected and likely have standing.
Legal Grounds That Can Actually Win
Unfairness is not a legal ground. You need evidence that the document does not reflect what the grandparent actually wanted. The person contesting carries the burden of proof.
Lack of Testamentary Capacity
A will is valid only if the grandparent, at the moment of signing, understood that they were making a will, had a general sense of what they owned, could identify the family members who would normally inherit, and grasped how the will would affect those people. A dementia diagnosis is not enough on its own. The question is whether the condition was severe enough to impair those specific abilities on the day the will was signed. Medical records showing advanced cognitive decline around the signing date are the strongest evidence.
Undue Influence
Undue influence means someone in a position of trust overpowered the grandparent’s own wishes and substituted their own. This is well beyond persuasion or persistent nagging. You generally need to show the influencer had a motive, had the opportunity, and actually exercised pressure strong enough to override the grandparent’s free will.
Courts look at the grandparent’s physical and mental condition, whether the beneficiary helped arrange or draft the will, whether the will departs sharply from earlier plans, whether the beneficiary held a position of trust such as caregiver or financial advisor, and whether the grandparent was isolated from other family. The classic pattern is a caregiver who moves in, cuts off contact with other relatives, and then takes the grandparent to a new attorney to rewrite the will.
Fraud or Duress
Fraud is intentional deception — for example, lying to the grandparent that a grandchild said terrible things in order to trigger a disinheritance. Duress is coercion, such as threatening to withdraw care unless the will is changed. Either can void the document, but both demand concrete evidence.
Improper Execution
Every state has formal rules for a valid will. Most require writing, a signature by the testator (or by someone else at their direction), and at least two witnesses who watched the signing or heard the testator acknowledge it. Some states recognize handwritten (holographic) wills under different rules. A rushed or sloppy signing ceremony, a witness who wasn’t actually present, or a questionable signature can all leave a will vulnerable.
How Long You Have to File
Every state imposes a strict filing deadline, and missing it permanently bars your claim. The window typically runs from a few months to two years after the will is admitted to probate. Some states give you as little as 90 days. The clock starts when probate opens, not when you learn the terms of the will, so delay is often fatal. If a contest is even on the table, talk to an estate litigation attorney immediately.
What a Contest Costs
Will contests are expensive. Attorney fees alone commonly start around $10,000 and climb substantially when expert medical testimony or heavy discovery is involved. Most estate litigation attorneys bill hourly; some will take a case on contingency for a percentage of the recovery. In some states, if you contested in good faith with reasonable cause, a court may order both sides’ fees paid from the estate, but that is not guaranteed, and you will usually need to fund the case yourself upfront.
No-Contest Clauses Can Cost You What You Already Have
Some estate plans include a no-contest clause (also called an in terrorem clause) stating that any beneficiary who challenges the document forfeits their share. The point is to make you weigh the upside of contesting against losing what you already have.
Enforcement varies by state. A handful, including Florida, refuse to enforce these clauses as a matter of public policy. Most states enforce them, but many apply a probable cause exception: if you had a genuine, evidence-based reason to believe the will was invalid, the court will not punish you for bringing the challenge even if you lose. Probable cause generally requires evidence that would lead a reasonable person to believe the contest has a substantial likelihood of success.
If you already stand to inherit something and the plan has a no-contest clause, that math is the first conversation to have with a lawyer. A grandchild receiving $50,000 under a will that leaves a sibling $500,000 has to decide whether the grounds are strong enough to risk the $50,000.
Contesting a Trust Is Different
Many grandparents transfer assets through living trusts rather than wills. Trust disputes are filed in civil court rather than probate court, with different timelines and procedures. The grounds are similar — capacity, undue influence, fraud — but trust cases often also involve claims that the trustee is mismanaging assets or breaching fiduciary duties.
One practical difference matters: a living trust can sometimes be challenged while the grandparent is still alive, which lets the grandparent testify about their own intentions. A will contest can only happen after death. If a trust was changed recently under suspicious circumstances and the grandparent is still living, time works against you.
When the Unequal Split Is Protecting a Disabled Grandchild
One common reason for an uneven distribution is a grandchild with a disability. Leaving a direct inheritance to someone receiving Supplemental Security Income (SSI) or Medicaid can disqualify them from the benefits they depend on, because SSI limits countable resources to $2,000 for an individual.[/mfn]
To avoid that, estate planners use a third-party special needs trust (sometimes called a supplemental needs trust) that supplements rather than replaces government benefits. As long as the beneficiary cannot revoke the trust or direct the trustee to pay for basic food and shelter, the Social Security Administration does not count it as a resource for SSI.1Social Security Administration. POMS SI 01120.200 – Trusts The trustee can still pay for therapy, transportation, recreation, education, and medical expenses Medicaid does not cover.
That is why a disabled grandchild’s share may look larger (it has to fund a lifetime of supplemental support) or smaller (the grandparent assumed benefits would cover most needs). The presence of a special needs trust is a strong signal that the plan reflects deliberate strategy, not favoritism. A third-party special needs trust also lets any remaining assets pass to family when the beneficiary dies, rather than being recovered by Medicaid.1Social Security Administration. POMS SI 01120.200 – Trusts Contesting that structure usually hurts the grandchild it was designed to protect.
Reasons That Are Not Manipulation
Before assuming something went wrong, think about whether the grandparent had a straightforward reason. Courts care about intent, and a documented reason makes a contest much harder to win.
- Lifetime gifts already made to one grandchild (college tuition, a down payment) that the grandparent evened out through the will.
- Caregiving by one grandchild compensated through a larger share.
- A deliberate choice to direct more to a grandchild with greater financial need.
- Estrangement or a distant relationship. Courts do not second-guess these decisions.
- Blended-family dynamics involving step-grandchildren, adopted grandchildren, or multiple branches of the family.
If the grandparent explained their reasoning in a letter of intent or in the estate plan itself, that evidence works against a contest.
Alternatives Before You Sue
A will contest is the nuclear option. It is public, expensive, and tends to finish off whatever family relationships survived the original grievance. Quieter paths sometimes get you what you actually want.
Read the Documents Carefully
Sometimes an uneven split is a drafting error, an outdated will that never got updated for a new grandchild, or a misunderstanding about what certain assets are worth. If you are a named beneficiary or an heir, you are generally entitled to a copy of the will or trust. Ask the executor or trustee and read it with an attorney before assuming the worst.
Mediation
Mediation brings everyone together with a neutral third party. It is faster, cheaper, and private. It also allows people to address the emotional dimension of the dispute, which a courtroom cannot. Because ongoing attorney fees drain the estate and trial rarely produces a clean winner, a negotiated compromise often leaves everyone better off.
Direct Family Conversation
Sometimes the grandchild who received more is willing to share once they understand how the result landed on the others, especially when circumstances behind the split have changed. A direct conversation, perhaps with a trusted relative or counselor helping, costs nothing and preserves relationships a lawsuit would destroy.
Whatever route you take, the most expensive mistake is acting on emotion before you understand your legal position. A one-hour consultation with an estate litigation attorney will tell you whether you have standing, whether your evidence supports a viable claim, and whether the potential recovery justifies the cost. Get that answer first.