When most people think about estate planning, they think about wills and trusts. Those documents matter. But they govern a smaller portion of most estates than people realize — and they’re routinely overridden by a simpler, more powerful document type that almost everyone fills out and almost nobody reviews: beneficiary designations.
The single most common — and most expensive — estate planning mistake we see in client households is an outdated or poorly thought-through beneficiary designation on a retirement account, life insurance policy, or transfer-on-death brokerage account.
Why beneficiary designations override wills
Most people assume their will controls who gets what. It doesn’t, for the assets that matter most.
Assets that pass by beneficiary designation (not by will):
- 401(k), 403(b), and other employer retirement accounts
- Traditional and Roth IRAs
- Annuities
- Life insurance death benefits
- HSAs
- Transfer-on-death (TOD) brokerage accounts
- Payable-on-death (POD) bank accounts
For a typical household at retirement, that list often represents 70–90% of the estate.
Whoever is named on the beneficiary form gets the money — regardless of what the will says. The will can be perfectly drafted, recently updated, and legally airtight. If your 401(k) beneficiary form names your ex-spouse from 1998, your ex-spouse gets the 401(k).
The most common mistakes
Outdated designations from a previous life. Ex-spouses on 401(k)s. Deceased parents still listed on old IRAs. Adult children from a first marriage on a life insurance policy that was supposed to support the second marriage’s household.
No contingent beneficiary. Primary beneficiary listed; if they predecease you, the asset reverts to the estate and goes through probate — defeating the entire point of beneficiary planning.
“To my estate” as the beneficiary. Sometimes done deliberately, almost always a mistake. Loses the ability to “stretch” inherited IRA distributions, exposes the asset to estate creditors and probate, and creates tax problems most heirs aren’t equipped to navigate.
Naming a minor child directly. Insurance companies and IRA custodians cannot pay benefits to a minor. The court appoints a conservator; lawyers’ fees consume a meaningful chunk; control of a large sum vests at age 18 or 21 with no guardrails. Should be a trust for the benefit of the minor, drafted carefully.
Naming a special-needs beneficiary directly. Disqualifies them from means-tested government benefits. Should be a special needs trust.
Equal-percentage assumptions that don’t add up. Two children, “50% to each.” Then a third child arrives and never gets added. Or one beneficiary is removed and the percentages still total 100% but allocate to the wrong people in the wrong proportions.
Trust named as beneficiary, but trust never updated for the SECURE Act. The 2019 SECURE Act fundamentally changed how inherited IRAs distribute. Many trusts drafted before then now produce dramatically worse tax outcomes than intended.
Why this happens
Beneficiary designations get filled out:
- Once, when you opened the account. Often during an HR onboarding session 20 years ago.
- Without coordination with any other planning document.
- In a moment of life that has since changed — single, first marriage, no kids, healthy parents alive, etc.
Then they sit. Untouched. For decades.
What to do
A complete beneficiary review takes about an hour and should happen:
- Annually, as part of year-end planning
- At every major life event — marriage, divorce, birth, death, adoption, second marriage
- When a trust is created or updated
- When you change jobs (the new 401(k) needs designations; the old one may have rolled to an IRA without them)
The review:
- Pull every account that has a beneficiary designation. Make a complete list.
- For each: Who is the primary beneficiary? Who is the contingent? Are the percentages right? Are minors named directly (problem)? Is the spouse / ex-spouse current?
- Coordinate with the will and any trusts. The estate plan should be a single coherent system, not a will plus 14 unrelated forms.
- Update each form. Many can be done online; some require a paper form returned to the custodian. Keep copies.
- Re-review annually.
The cost of getting this wrong
Real cases we’ve seen (or heard cleanly documented):
- $1.2M 401(k) inherited by an ex-spouse instead of current spouse and children. No legal recourse — the form controlled.
- A life insurance policy paid to a minor child directly; $400K tied up in conservatorship for years, with attorney fees consuming a meaningful percentage.
- A trust beneficiary on an IRA that, post-SECURE Act, forced full distribution within 5 years instead of the 10-year stretch the trust was designed for. ~$200K of additional tax over the distribution period.
These are the easiest planning mistakes to prevent and among the costliest to discover after the fact.
If you can’t immediately tell us who the beneficiaries are on every retirement account and life insurance policy you own — and you’re our client or you’d like to be — that’s the first conversation worth having. Reach out.
General educational information. Beneficiary planning interacts with state law, tax law, and trust drafting. Specific decisions require coordination with your estate attorney, tax advisor, and financial planner.