Old retirement accounts are often set up at places of employment but can be forgotten or lost track of when changing jobs, which can make it difficult to administer estates, according to Wills, Trusts & Estates Prof Blog in "How to Find Your Lost 401(k)."
Currently the U.S. Pension Benefit Guaranty Corp. has a database of traditional pension plans that allows people to find any lost accounts. The agency would like to make that database easier to search and would like to expand it to include defined-contribution pensions and 401(k) accounts.
However, for now, inclusion of 401(k) accounts would be voluntary and there are other companies attempting to corner the market. A bill is in Congress that would make it mandatory to create a nationwide searchable database.
If you have old retirement accounts you cannot locate, you might want to contact your representative in Congress to urge passage of the bill.
Reference: Wills, Trusts & Estates Prof Blog (Sept. 20, 2016) "How to Find Your Lost 401(k)."