A release from the Investment Company Institute tells us that, "Retirement Assets Total $33.6 Trillion in Fourth Quarter 2022." It includes data tables showing that money market funds held in retirement accounts rose to $602 billion (from $583 billion) in total, or 13% of the total $4.777 trillion in money funds. MMFs represent just 5.9% of the total $10.136 trillion of mutual funds in retirement accounts. This release says, "Total US retirement assets were $33.6 trillion as of December 31, 2022, up 3.9 percent from September but down 14.7 percent for the year. Retirement assets accounted for 30 percent of all household financial assets in the United States at the end of December 2022. Assets in individual retirement accounts (IRAs) totaled $11.5 trillion at the end of the fourth quarter of 2022, an increase of 3.9 percent from the end of the third quarter of 2022. Defined contribution (DC) plan assets were $9.3 trillion at the end of the fourth quarter, up 4.3 percent from September 30, 2022. Government defined benefit (DB) plans—including federal, state, and local government plans -- held $7.6 trillion in assets as of the end of December 2022, a 4.3 percent increase from the end of September 2022. Private-sector DB plans held $3.1 trillion in assets at the end of the fourth quarter of 2022, and annuity reserves outside of retirement accounts accounted for another $2.2 trillion." The ICI tables also show money funds accounting for $428 billion, or 9%, of the $5.006 trillion in IRA mutual fund assets and $174 billion, or 3%, of the $5.130 trillion in defined contribution plan holdings. (Money funds in 401k plans totaled $120 billion, or 3% of the $4.049 trillion of mutual funds in 401k's.)