How many Americans are 401(k) millionaires? How to kick-start your savings

Core Insights - The 401(k) retirement plan is a popular savings vehicle for Americans, holding nearly $9.3 trillion in assets for 70 million participants as of Q2 2025 [1] - The average balance in 401(k) accounts is $127,100, with baby boomers having the highest average balance of $267,900 [2][3] - Only 595,000 individuals are classified as 401(k) millionaires, highlighting the challenge of accumulating significant retirement wealth [3] Savings Behavior - Building wealth for retirement requires early and consistent contributions, with starting early being crucial for maximizing growth through compound interest [5] - A practical example shows that saving $420 monthly at a 7% return starting at age 25 can yield over $1 million by age 65, while starting at age 35 results in approximately $476,000, demonstrating a loss of over $500,000 in potential wealth [6]