The answer to this question depends entirely on who you are trying to disinherit. New Mexico law treats spouses and children very differently, and getting this wrong in your estate plan can produce outcomes that are the opposite of what you intended.
The short version: you can disinherit an adult child in New Mexico, but you cannot fully disinherit a spouse. A surviving spouse has legal protections that exist regardless of what your will says. Those protections cannot be eliminated through a will alone, though they can be waived by agreement. Children, including adult children and stepchildren, have no automatic inheritance rights that survive your express decision to exclude them, as long as the exclusion is done correctly.
This article explains how disinheritance works in New Mexico, what the law protects and what it doesn't, and what you need to do if disinheritance is part of your estate plan.
Disinheriting a Spouse in New Mexico: What the Law Allows
New Mexico is a community property state, which creates the first and most significant protection for a surviving spouse: they already own half of all community property. That half is not yours to give away. It belongs to your spouse during your lifetime and continues to belong to them after your death. Your will controls only your half of community property and your separate property.
This means that a will that attempts to leave all community property to someone other than your spouse can only operate on your half. Your spouse's half passes to them automatically, regardless of what your will says.
Beyond community property, New Mexico's Uniform Probate Code provides additional protections for surviving spouses.
The elective share
Under New Mexico law, a surviving spouse is entitled to an elective share of the deceased spouse's augmented estate. The elective share is a protection against a spouse being completely cut out of an estate through a will that leaves everything to others.
The augmented estate calculation under New Mexico's Uniform Probate Code is more complex than a simple percentage of the probate estate. It takes into account the couple's combined assets and the length of the marriage, with the surviving spouse's share increasing with the duration of the marriage. The details of the elective share calculation require review with a New Mexico estate planning attorney, as the specific mechanics depend on individual asset structures and marriage length.
The practical implication is clear: a will that leaves nothing to a surviving spouse does not actually accomplish full disinheritance in New Mexico. The surviving spouse retains the right to elect against the will and claim their statutory share.
The omitted spouse
A separate protection applies when a spouse is omitted from a will entirely, which typically happens when the will was executed before the marriage. Under New Mexico's Uniform Probate Code, a spouse who married the testator after the will was executed and who is not provided for in the will is entitled to a share of the estate. This is called the omitted spouse rule, and it operates differently from the elective share.
The omitted spouse rule is a safeguard against unintentional omission. If you intend to omit your spouse, the will should address this expressly rather than leaving the omission to implication.
How to actually limit a spouse's inheritance
The most reliable way to limit what a spouse receives is through a valid prenuptial or postnuptial agreement in which the spouse waives their community property rights, elective share rights, or both. A waiver in a prenuptial or postnuptial agreement that meets New Mexico's requirements for validity is enforceable and can effectively limit a spouse's inheritance rights to whatever the agreement specifies.
A prenuptial agreement executed before the marriage and a postnuptial agreement executed during the marriage can both accomplish this goal. Both require voluntary execution, full financial disclosure, and independent legal advice for the agreement to hold up. An agreement signed under duress, without adequate disclosure, or in a way that is fundamentally unfair may be challenged and invalidated.
Disinheriting an Adult Child in New Mexico: What the Law Allows
Adult children have no automatic inheritance rights in New Mexico. Unlike a spouse, an adult child does not have an elective share or any other statutory right to inherit from a parent who deliberately chooses to exclude them.
This means that disinheritance of an adult child is straightforward in principle: you simply do not name them in your will, or you expressly state in the will that they are to receive nothing. Either approach is legally effective.
The express approach, including language in the will that specifically identifies the child and states they are intentionally excluded, is generally the more reliable one. It removes any ambiguity about whether the omission was intentional, which is relevant to the omitted child rule discussed below.
Why the method matters
Simply not mentioning a child in a will is not always sufficient, and the reason has to do with timing.
The omitted child rule
New Mexico's Uniform Probate Code protects children who were born or adopted after the execution of a will and who are not mentioned in the will. If you had a child after signing your will and never updated the will to include or address that child, the omitted child is entitled to a share of the estate under the intestate succession formula.
This protection exists to prevent unintentional omission. A parent who had two children when the will was signed and then had a third child but forgot to update the will didn't intend to exclude the third child. The law protects against that outcome.
For children who were alive and known to the testator when the will was signed, the omitted child rule does not apply. If you had a child and simply chose not to include them, that omission is treated as intentional and the child receives nothing. But this distinction, between a child born before the will was signed and omitted, versus a child born after the will was signed and omitted, makes a difference.
The safest practice is to address the child expressly in the will, either by including them or by expressly excluding them with a statement that the omission is intentional. This removes any argument about whether the omission was deliberate.
Contesting a disinheritance
A disinherited adult child may attempt to contest the will on grounds that don't depend on having an inheritance right, including claims that the testator lacked mental capacity when the will was signed, that the will was the product of undue influence by another person, or that the will was forged or improperly executed.
These are not claims about the right to inherit. They are claims about whether the will itself is valid. A will that is found to be invalid is set aside, and the estate passes under the prior will or under intestate succession, which may give the child a share.
To minimize the risk of a successful will contest, a disinheritance should be executed as part of a carefully drafted will prepared by an attorney, signed when the testator's capacity is clear, with appropriate witnesses, and ideally with a contemporaneous explanation of the reasons for the exclusion, though the reasons themselves do not need to be stated in the will.
Stepchildren: No Automatic Rights
Stepchildren have no automatic inheritance rights under New Mexico law. Intestate succession passes assets to biological children and legally adopted children. A stepchild who was never legally adopted by the stepparent has no right to inherit under a will that doesn't mention them, and no right to inherit if the stepparent dies without a will.
If you want a stepchild to inherit from you, you need to include them specifically in your will or trust. If you don't want a stepchild to inherit, simply not mentioning them is sufficient. There is no need to expressly disinherit a stepchild who was never adopted.
Disinheritance and Community Property: A Critical Interaction
Because New Mexico is a community property state, disinheritance planning for a spouse requires particular attention to how assets are characterized.
Your half of community property is yours to give. Your spouse's half is not. A disinheritance plan that attempts to direct community property to children from a prior relationship, for example, can only operate on your half. The other half belongs to your spouse regardless.
Separate property, assets you owned before the marriage or received as gifts or inheritances during the marriage and kept separate, is more fully controllable through your estate plan. You can leave your separate property to anyone you choose, subject to the elective share rights your spouse retains.
For any disinheritance planning that involves significant assets, understanding which assets are community property and which are separate property is an essential first step. An estate planning attorney familiar with New Mexico's community property framework can help you map your assets before drafting any documents.
Practical Considerations Before Disinheriting
Disinheritance has legal and practical dimensions. A few things worth considering before proceeding:
Will contests are more likely after disinheritance. A child or other family member who was expected to inherit and receives nothing has a stronger motivation to contest the will than one who received something. While a disinheritance can be legally airtight, litigation is always a possibility, and the cost and emotional toll on the family can be significant.
Clear documentation of capacity and intent helps. A will executed with clear evidence of the testator's capacity and intentional decision-making is harder to contest. Working with an attorney, signing the will in a standard execution ceremony with proper witnesses, and maintaining records of the planning conversations can all reduce the risk of a successful contest.
Trusts can provide additional protection. A revocable living trust that is used to hold and distribute assets avoids probate, which means it avoids the public court process where a will contest occurs. While a trust can also be contested, doing so is generally more difficult and less common than contesting a will. For disinheritance situations where a contest seems likely, a trust-based plan may provide somewhat stronger protection.
Consider a no-contest clause. A no-contest clause, also called an in terrorem clause, is a provision in a will that disinherits any beneficiary who challenges the will. In New Mexico, no-contest clauses are generally enforceable, but only against beneficiaries who have something to lose by contesting. A beneficiary who receives nothing has nothing to lose and will not be deterred by a no-contest clause. A beneficiary who receives a modest bequest might be deterred from contesting a larger expected share. The strategic use of a no-contest clause requires careful thought about who the likely challengers are and what they stand to gain or lose.
How Genus Law Group Can Help
Disinheritance planning requires careful drafting, attention to New Mexico's community property framework, and a realistic assessment of what challenges may arise. At Genus Law Group, we help New Mexico families navigate these decisions with clarity about what the law allows and what the risks are.
We serve clients in Albuquerque, Las Cruces, and throughout New Mexico.
Call us at (505) 317-4455 in Albuquerque or (575) 215-3500 in Las Cruces, or reach us through the contact form at genuslawgrp.com.
Frequently Asked Questions
Can I leave my entire estate to charity and disinherit my children in New Mexico?
Yes, with one caveat: you cannot disinherit a surviving spouse through your will alone. If you are married, your spouse retains community property rights and elective share rights regardless of what your will says. For adult children, there is no legal right to inherit, so a will that leaves everything to charity and nothing to your children is legally effective as long as it is properly executed and the children were known to you when the will was signed.
Does a no-contest clause protect against a disinherited child contesting a will in New Mexico?
Only partially. A no-contest clause is effective against beneficiaries who receive something under the will and risk losing it by contesting. A child who is completely disinherited has nothing to lose and will not be deterred by a no-contest clause. For that reason, some attorneys recommend leaving a small bequest to a potentially contentious heir, enough that the no-contest clause creates a real deterrent. Whether this approach makes sense depends on the specific family situation and should be discussed with your estate planning attorney.
What if I disinherited a child and then had a new child after signing my will?
The new child would be protected by New Mexico's omitted child rule, which gives a share of the estate to children born or adopted after the will was executed who are not mentioned in the will. The rule exists to prevent unintentional omission. If you have a new child after signing your will, you should update your will to either include the new child or expressly address their exclusion. Failing to update the will creates uncertainty about your intentions.
Can my spouse waive their right to an elective share in New Mexico?
Yes. A spouse can waive elective share rights, community property rights, or both through a valid prenuptial or postnuptial agreement. The waiver must be voluntary, made with adequate financial disclosure, and the spouse should have had the opportunity to consult independent legal counsel. A waiver that does not meet these requirements may be challenged. If limiting a spouse's inheritance is a goal, a prenuptial or postnuptial agreement drafted with the assistance of a New Mexico attorney is the reliable path to accomplish it.
