The standard for signing a will is lower than almost everyone expects, and lower than the standard for signing a contract. A person with a documented dementia diagnosis can make a perfectly valid will on a clear Tuesday afternoon.
That is the hardest conversation I have with adult children who watched a parent decline for years and assume the diagnosis wins the case by itself. It does not.
Two different standards
California uses a lower bar for testamentary acts than for commercial ones. Trusts sit awkwardly between the two, and which standard applies can depend on how complicated the document is. A simple revocable trust that functions like a will is often measured by the will standard. A trust with complex tax provisions and layered powers can be measured by the higher one.
| Standard | What the person must be able to do |
|---|---|
| Testamentary capacity, used for wills | Understand that they are making a will and what a will does, understand and recall the general nature of what they own, and remember their relationships to the people who would normally inherit |
| Contractual capacity, used for complex instruments | The above, plus the ability to understand and appreciate the rights and duties involved and the probable consequences of the transaction |
| Common disqualifiers under either | A delusion or hallucination that causes the disposition, or a mental deficit affecting memory, planning, or reasoning severe enough to correlate with the specific act |
Why the diagnosis alone loses
Capacity in California is measured at the moment of signing. Not that year, not that season. That afternoon. Cognitive impairment fluctuates, and the law recognizes lucid intervals, so testimony that Dad was confused most of the time in March does not defeat a document he signed on March 14 if the attorney and two witnesses describe a coherent conversation.
The corollary is that timing evidence is everything. Hospital notes from the day before. The pharmacy record showing what he had taken that morning. A mini mental state exam from the same week. Anything that anchors the question to the actual date.
The document that decides most of these
The drafting attorney's file. Intake notes, who scheduled the appointment, who was in the room, what questions the attorney asked, whether the attorney did any capacity screening at all. A careful attorney who documented a real conversation makes a capacity claim very hard. A file with three lines in it and a caregiver listed as the contact makes the same claim much easier.
What we gather
- Complete medical records for at least a year on either side of the signing, including imaging and any neuropsychological testing
- Medication lists, because sedatives and pain management regimens matter enormously
- The attorney's file and, in litigation, the attorney's deposition
- Witness accounts from people with no stake in the outcome: a physical therapist, a longtime neighbor, the pastor
- A retained expert, usually a geriatric psychiatrist or neuropsychologist, to review the records and give an opinion tied to the date
“I have had two clients bring me videos. Both were taken by the family member who benefited, both showed a parent being asked leading questions, and both hurt the side that made them more than they helped. If you are thinking about recording a signing, think about how it looks to a judge who watches the whole tape.”
Delia Vasquez-HartCost, and when it is not worth it
Capacity litigation is hourly work on a retainer, and the expert alone is a serious expense before you count depositions. These cases are often paired with undue influence claims, since the same facts feed both, and pleading them together does not usually double the cost.
But I turn these down regularly. If the estate is a condo in Palms with a mortgage on it and three siblings, the fee exposure can eat the difference between winning and losing. I would rather tell you that in month one than in month fourteen.
Questions we get asked
My father had Alzheimer's. Is that enough?
It is strong evidence and it is not conclusive. The question is what he could understand on the specific day he signed, which is why the records from that week matter more than the diagnosis.
Does a doctor's letter saying he lacked capacity settle it?
It helps, especially if it is close in time and the doctor examined him. It does not bind the court, and the other side will produce its own opinion.
What if he was under a conservatorship?
That shifts the picture considerably, though even a conservatee can retain testamentary capacity in some circumstances. It is a good fact for a challenge, not an automatic one.
Can capacity and undue influence be argued together?
Yes, and they usually are. They rest on overlapping evidence and a court can find either one.
Next step
Request your parent's medical records now, before you decide anything, because providers take weeks and some purge on a schedule. Then bring what you have to a free 45-minute consultation. Call (310) 555-0219.