How Korean Courts Judge Will Capacity in Early Stage Dementia
Many family members who come to our office walk in with the same sentence. "Father was barely conscious, and yet a gift went through in that state." Or: "Mother was in a nursing home, and our oldest brother wheeled her out to pick up her seal-impression certificate." This article sets out how far Korean courts typically recognize testamentary and donative capacity in a person with dementia, and what families need to prepare in advance to prevent a dispute.
Dementia does not automatically mean incapacity
The most common misconception is that any will or gift made in a state of dementia must be void. Korean courts do not take that view. The age of majority is 19, and an adult is presumed to have mental capacity. A dementia diagnosis alone does not automatically negate mental capacity.
The court's standard is not the diagnostic name but the cognitive state at that moment. Early-stage dementia typically yields a conclusion that recognizes mental capacity and testamentary capacity, and only when the disease has progressed to mid-stage or beyond does room open up to challenge validity.
In consultations, families often say "Father could barely speak at that time," but when the medical records are opened the records frequently show a transition from early to mid-stage dementia. Outcomes in that range are typically hard to overturn.
MMSE scores and the trend in Korean case law
The most representative screening tool for dementia severity is the MMSE (Mini-Mental State Examination). The general tendencies seen in practice can be summarized as follows.
| MMSE range | Typical clinical classification | Tendency in capacity disputes |
|---|---|---|
| 24 or above | Close to normal | Capacity typically recognized |
| 18 to 23 | Mild cognitive decline | Capacity typically still recognized |
| 10 to 17 | Moderate dementia | Real room to litigate opens up |
| Below 10 | Severe dementia | Capacity typically denied |
These ranges are tendencies, not absolute thresholds. Even at the same score, the specific narrative in the chart, the doctor's opinion letter, and the consistency of other contemporaneous documents are all reviewed together.
Three risk patterns we see most often
When we trace inheritance disputes back to the point they began, they typically fall into one of three patterns.
- First, taking the early-stage dementia parent to the local administrative center to obtain a seal-impression certificate, and using that seal to transfer the title to real estate.
- Second, transporting a parent in a confused state to a notary office, or arranging an on-site notarial appointment, to produce a notarized will.
- Third, drafting a new will or notarization at the early-stage phase to neutralize a will drafted earlier while the parent was healthy.
The third pattern is especially dangerous. Under Korean law, the latest will controls, so the comfort of "we wrote one years ago while she was healthy" is not enough.
The strongest preventive measure is filing for adult guardianship
Once early signs of dementia appear, the single strongest preventive measure is to use the adult guardianship (or limited guardianship) system. From the moment a guardianship order issues, the guardian manages the parent's assets under the supervision of the court, and any gift or disposition beyond the parent's ordinary living expenses typically requires the court's approval.
Courts typically do not approve a large gift directed solely at a particular child. That itself becomes the most efficient way to protect the parent's assets.
- Once a parent is diagnosed at the early stage, consider a guardianship petition as soon as possible.
- If there is a dispute over who within the family should serve as guardian, conceding the suspected family member to be the guardian is typically safer (because that person comes under court supervision).
- A third-party guardian (an attorney, for example) involves some cost, but if the family cannot reach agreement, it is a safer choice.
"Skip the treatment and rush the gift through" is the most dangerous choice
This is a darker corner of the practice, but it is a pattern attorneys see often. The child who notices the parent's early-stage symptoms first quickly secures a gift or a will without telling the other siblings.
To establish dementia, medical records are needed. That is why some children intentionally avoid taking the parent to a doctor while a gift is being completed. After death, when a dispute begins, the only thing left is the testimony "Father was confused at the time" with no medical record to back it up, and courts typically end up recognizing capacity.
If you suspect dementia in a parent, building a medical record is the very thing that protects the whole family. Without medical records, almost any post-death claim is typically hard to prove.
Five items children should check in advance
- The moment suspected dementia symptoms appear, take the parent for an evaluation and create a record.
- Preserve MMSE and other cognitive screening results in chronological order.
- Periodically check seal-impression issuance, real-estate title changes, and unusual financial transactions.
- Discuss in a family meeting whether to file for adult guardianship.
- If possible, arrange a will or a will-substitute trust through an attorney while the parent is still healthy.
Frequently asked questions
Q. My parent is in early-stage dementia, and my older brother has already received a real-estate gift. Can it be reversed? A. It is typically difficult. That said, if the medical record around the time of the gift, the surrounding circumstances, or evidence of coercion in obtaining the seal-impression certificate is available, there is room to challenge. We recommend organizing the materials and starting a chat consultation now.
Q. Will applying for adult guardianship make family relationships worse? A. In the short term it can feel uncomfortable, but in the long term it typically reduces disputes. Once a guardianship order issues, the parent's assets are managed under court supervision, and the contest over "who can grab them first" effectively disappears.
Q. There is already a notarized will, and another new will was made later. Which one controls? A. Under Korean law, the latest will controls. However, if mental capacity at the time of the latest will is negated, that will becomes void and the immediately preceding will controls.
Closing
Where dementia and inheritance meet, families collapse fastest. Three steps - building a medical record in advance, filing for guardianship at the appropriate moment, and arranging the will while the parent is healthy - are typically the most effective prevention. If you are not sure which stage your own family is at, we recommend a quick check through a consultation.
Written by attorney Roh Jongeon, Managing Partner of Jonjae Law Firm / Last reviewed 2026-05-30
This article is intended as general legal information and does not guarantee any particular outcome. Each case turns on its own facts, so please retain an attorney for an individual consultation before acting.
