A carefully drafted will can be quietly overridden by a form somebody filled in years earlier and never looked at again.
How it happens
Retirement accounts, life insurance and certain other assets pass by beneficiary designation. They go to whoever is named on the account paperwork, regardless of what a will says. Jointly held property passes by operation of law in much the same way. A will that contradicts those designations does not override them — it simply produces a result nobody intended.
Where it bites hardest
After a divorce, and after a death in the family. A designation naming a former spouse, or a parent who has since died, is among the most common and most painful errors in estate planning, and it usually surfaces at the worst possible moment.
The fix is small
Pull every beneficiary designation you have — employer retirement plans, IRAs, life insurance, payable-on-death accounts — and read who is actually named. It is an afternoon of administration, and it is the single highest-value hour in most estate plans.
General information about New York law, not legal advice. Outcomes depend on the facts of your situation.