Review old pay stubs, W-2s, and tax returns for employer names and retirement deductions
Make a list of every past employer
Contact each former employer’s HR or benefits department
Ask whether the company still sponsors the old 401(k) plan
Search your old emails, paper files, and account statements for plan provider names
Contact the plan administrator or recordkeeper directly if you know the provider
Check the National Registry of Unclaimed Retirement Benefits
Search your state’s unclaimed property database
Use the U.S. Department of Labor’s abandoned plan search tools
Check the IRS Form 5500 database for plan information
Call the plan’s customer service using any old account numbers or statements
Contact the plan’s trustee or custodian if listed on old documents
Ask whether your balance was rolled over, cashed out, or left in the plan
Verify whether you changed your address and missed plan notices
Check with the Social Security Administration earnings record for past employers if needed
Keep your identification, Social Security number, and employment dates ready when you inquire