The Interrelation of Undue Influence and Testamentary Capacity in Estate Planning and Probate Proceedings

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Undue influence is a legal claim that arises when someone exerts pressure on another person to make a decision that they would not have made otherwise. In Michigan, undue influence claims are often brought in the context of wills, trusts, and other estate planning documents and even with such things as investment accounts and life insurance beneficiary designations.

To establish undue influence in Michigan, the person contesting or challenging the validity of the document must show that the person who made the document was vulnerable to being influenced and that the influencer had the opportunity to exert that influence. They must also show that the influencer actually used that opportunity to exert influence and that the document reflects the influencer's wishes rather than the wishes of the person who made it.

There are several factors that courts in Michigan consider when determining whether undue influence has occurred, including the relationship between the influencer and the person who made the document, the timing of the document's creation, and whether the document reflects the person's long-term wishes or a sudden change.

If you believe that someone has exerted undue influence over a loved one in Michigan, it is important to speak with an experienced attorney who can help you navigate the legal process and protect your loved one's wishes.

Lack of testamentary capacity is a legal concept, claim, or defense that arises when a person is unable to understand the implications and consequences of creating or modifying a will or other estate planning document. In Michigan, this concept plays a crucial role in determining the validity of these documents. This article will provide an overview of the lack of testamentary capacity, its implications on estate planning, and the legal process involved in challenging a will based on this ground.

Testamentary Capacity: The Legal Standard in Michigan

In Michigan, the legal standard for testamentary capacity requires that the person creating or modifying a will or trust must:

  • Understand the nature and extent of their property;
  • Know the natural objects of their bounty (i.e., their close family members and other potential beneficiaries);
  • Understand the disposition they are making; and
  • Be able to relate these elements to each other and form a rational plan for the distribution of their property.

If a person lacks testamentary capacity at the time they create or modify a will or trust, the document may be declared invalid.

Factors Affecting Testamentary Capacity

Several factors can affect a person's testamentary capacity, including age, illness, cognitive decline, and mental health conditions. A temporary lack of capacity due to factors such as medication or intoxication may also impact the validity of a will or trust. It is important to note that a diagnosis of a mental health condition or cognitive decline does not automatically mean that a person lacks testamentary capacity; they may still be able to meet the legal standard.

Challenging a Will or Trust Based on Lack of Testamentary Capacity

To challenge a will or trust based on a lack of testamentary capacity in Michigan, a person must initiate a legal proceeding known as a will or trust contest. This typically involves filing a petition with the probate court and presenting evidence that the testator lacked testamentary capacity at the time they created or modified their will or trust.

Evidence that may be presented in a will or trust contest can include:

  • Medical records documenting the testator's cognitive decline or mental health condition;
  • Testimony from witnesses who observed the testator's behavior around the time the will or trust was created or modified;
  • Expert testimony from medical or legal professionals regarding the testator's mental state; and
  • Any other relevant evidence that supports the claim of lack of testamentary capacity.


Lack of testamentary capacity is an important concept in Michigan estate planning law, as it can impact the validity of a will, trust, or other estate planning document. If you believe that a loved one's estate plan was created or modified while they lacked testamentary capacity, it is essential to consult with an experienced probate or estate planning attorney who can guide you through the process of challenging the document in court.

If you have any questions about the issues addressed in this article, or if you would like a copy of any of the materials mentioned in it, please do not hesitate to reach out to Greg Jenkins of Kuhn Rogers PLC.

Categories: Estate Planning