U.S. retirement assets totaled $39.4 trillion at the end of 2021, according to the Investment Company Institute. Individual retirement accounts, with $13.9 trillion of assets, had the highest total. Assets in 401(k) accounts were $7.7 trillion, and there was another $3.3 trillion in other defined contribution plans (e.g., 403(b) plans and the federal government's Thrift Savings Plan).
Since 2007, IRA assets grew by 196% through the end of 2021, while 401(k) and other DC plan assets increased by 157% and 106%, respectively. Private and public defined benefit plan asset growth has lagged at 46% and 90% respectively. Annuities also had lower growth, increasing 73% over that span.