In short: In Florida, a person has testamentary capacity if, when signing the will, they knew the natural objects of their bounty, understood in a general way the nature and extent of their property, and had a general understanding of the practical effect of the will. Capacity is judged at the moment of execution, so a dementia diagnosis alone doesn’t void a will, and a will signed during a lucid interval can be valid.
Every will contest Matt sees now seems to involve the same three words: dementia, caregiver, change. Capacity is usually the first question.
The Florida Test
The Florida Supreme Court in In re Estate of Weihe (1973), quoting Hamilton v. Morgan (1927), framed capacity as whether the testator, “at the time he executed the will, knew the objects of his bounty, understood, in a general way, the nature and extent of his property and had a general understanding of the practical effect of the will as executed.”
Three things, in plain language:
- Who. Does she know who her family is?
- What. Does she understand, generally, what she owns?
- Effect. Does she understand what this document does?
It’s a low bar on purpose. The law doesn’t require perfect memory or sound judgment.
Capacity Is Judged at the Moment of Signing
The question isn’t whether Mom had dementia. It’s whether she had capacity on the afternoon she signed. In Weihe, medical evidence from years before execution wasn’t enough to prove incapacity at signing. Florida courts also recognize that a will signed during a lucid interval can be valid, even after an incapacity finding.
That’s why Matt’s office evaluates capacity in every will, POA, and estate planning meeting, and documents it.
Capacity and Undue Influence Travel Together
Cognitive decline makes people vulnerable. Early-stage dementia can be hard to see: a client can come in on a clear day, then slip. That’s when a caregiver, spouse, or child steers changes the person wouldn’t otherwise make. Lack of capacity and undue influence are separate claims, but they’re usually pleaded together. See undue influence and the Carpenter factors.
Deeds, POAs, and Beneficiary Changes
Capacity questions aren’t limited to wills. Deeds, powers of attorney, gifts, and POD designations made in the last years of life are challenged on the same facts. The 2026 oral argument below involves a family deed attacked for dementia and undue influence. See beneficiary changes before death.
Building or Defending a Capacity Case
- Medical records and physician testimony from around the signing date
- The drafting lawyer’s file and notes, and the witnesses
- Bank and financial behavior: missed bills, scams, unusual transfers
- Witnesses who saw the person near that date
- For planners: a contemporaneous capacity evaluation, or a video of the signing, for anyone at risk
Deadlines
A will contest generally must be filed within 3 months after service of the notice of administration (§ 733.212(3)). See how to contest a will in Florida.
Watch: the videos behind this article
Florida Attorney EXPOSES: How to Tell if Parent Has Capacity (Before It’s Too Late)
Elder Exploitation Is a Hidden Epidemic Like the #MeToo movement, this crisis will explode
More Short Videos on This Issue
Watch the Real Appellate Arguments
These are recordings of actual Florida appellate oral arguments, posted on the channel. Watch how the judges question both sides. Read the written opinion before relying on any outcome: an argument is not a ruling.
Will Invalid for Lack of Testamentary Capacity? Florida 3rd DCA Oral Argument | Weidner Law
Family Deed Under Fire — Dementia, Undue Influence & a Contested Property Transfer
Go Deeper
- Undue Influence in Florida Wills
- How to Contest a Will in Florida
- Caregiver Changed the Beneficiary Before Death? Florida POD Accounts, POA Abuse, and What You Can Do
- How to Avoid Guardianship in Florida: The Power of Attorney Is the Least Restrictive Alternative
Frequently Asked Questions
What is testamentary capacity in Florida?
The ability, at the time of signing, to know the natural objects of one’s bounty, understand in a general way the nature and extent of one’s property, and have a general understanding of the practical effect of the will. Florida courts have applied this test since at least Hamilton v. Morgan (1927).
Does dementia mean a will is invalid in Florida?
Not automatically. Capacity is measured at the moment the will is signed. A person with dementia may still have capacity during a lucid interval. The challenger has to prove incapacity at execution, usually with medical records and witness testimony from around that date.
What’s the difference between lack of capacity and undue influence?
Lack of capacity means the person couldn’t understand what they were signing. Undue influence means someone overpowered their free will. They often appear together: cognitive decline makes a person more vulnerable to influence.
How do you prove someone lacked capacity when they signed a will?
With medical records, physician testimony, testimony of people who saw the person near the signing date, the drafting lawyer’s notes, and evidence of how the person handled their affairs. Proof from years before or after is weaker.
Talk to a Florida probate litigator
Weidner Law, P.A. handles Florida probate, trust, guardianship, and will disputes from St. Petersburg. If you need a probate litigation lawyer in St. Petersburg or anywhere in Florida, call (727) 954-8752 or email weidner@mattweidnerlaw.com.
Read the law yourself, free: the full Florida Probate Code and Probate Rules and the Florida Trust Code are on floridarules.net.
This article is general information about Florida law, not legal advice about your situation. Reading it, watching the videos, or contacting the firm does not create an attorney-client relationship. Every case turns on its own facts, and past results do not guarantee a similar outcome. The hiring of a lawyer is an important decision that should not be based solely upon advertisements.
