A significant amount of money, reportedly $2.1 trillion, is sitting in forgotten 401(k) accounts. The number of abandoned accounts is substantial, with one estimate suggesting 31.9 million accounts, though the total amount in these accounts is uncertain, with one report questioning the $2.1 trillion figure by suggesting an alternative amount of $1.7 trillion. These forgotten funds may belong to individuals who have changed jobs or experienced other life changes, leaving their retirement savings unclaimed.