There are a number of tricks to grow a tax‑advantaged 401(k) or IRA into a fortune. More Americans have built up supersize sums in their tax‑advantaged retirement accounts. But those with more modest means can also grow their own nest eggs bigger than they might think.

Nearly 12,000 taxpayers had individual retirement accounts with at least $10 million in 2024, the latest year for which figures are available, according to new data prepared by the nonpartisan Joint Committee on Taxation. That’s up from 3,625 with similar balances in 2019, the analysis of anonymized tax‑return data found.

The surge shows that even modest savers can achieve significant growth by contributing consistently, capturing employer matches, and choosing low‑cost index funds that track broad market returns. Starting early lets compound interest work its magic over decades. Even small increases in contribution rates—such as raising savings from 5% to 7% of pay—can dramatically boost the final balance.

Financial planners advise setting up automatic contributions, reviewing asset allocation annually, and avoiding early withdrawals that trigger taxes and penalties. With discipline, a modest income can still lead to a comfortable retirement.