MoMo Productions / Getty Images Designate your heirs as your beneficiaries to ensure they receive your 401(k). Key Takeaways Your 401(k) passes to the person you name on a beneficiary form—not through your will. Spouses and non-spouses face different rules and tax implications when inheriting a 401(k). Forgetting to update your beneficiary or leaving it blank can lead to probate and unintended recipients. Your 401(k) could be one of your biggest assets. But what happens to it after you die? Unli ...