Retirement accounts
Contact plan administrators or HR; 401(k) and IRA beneficiaries on file usually receive forms directly
Some steps differ by region inside the country.
Where
The plan administrator or IRA custodian, and the employer's HR for workplace plans. The Department of Labor and PBGC can help trace lost plans.
How
List every employer they ever had, then contact each plan, not just the most recent one.
Ask each custodian for the beneficiary designation on file and the date of death value.
Have each beneficiary contact the custodian directly to make their own election, since the tax treatment depends on it.
Use the Department of Labor's abandoned plan database or PBGC's unclaimed pension search for plans you cannot trace.
What to bring
A certified copy of the death certificate
The account or plan number
Each beneficiary's identification and Social Security number
Letters testamentary, only if the estate is the beneficiary
Timing
Beneficiary claims are commonly processed within 4 to 12 weeks once the paperwork is complete.
Sources
This is practical information, not legal, medical, or financial advice.