401k statistics can look contradictory because the sources measure different things. ICI measures the whole market. Fidelity and Vanguard measure participants on their own workplace platforms. BLS measures access and participation among workers. IRS data explains the legal contribution limits.
Taken together, the current picture is clear: the 401(k) system is huge, uneven, and still highly dependent on workplace access. ICI estimated $9.9 trillion in 401(k) assets at the end of Q1 2026. Fidelity put the average 401(k) balance on its platform at $141,000 in Q1 2026. BLS found that 65% of civilian workers had access to a defined contribution plan in March 2025, but only 45% participated.
Use this page as a citable reference for 401k statistics, 401k participation statistics, and 401k by age data. It is informational only and is not investment, tax, or legal advice. For product-level options, see our guide to best 401(k) plans.

