401(k) Plans

What the Data Shows About 401(k) Plans

A 401(k) is a defined contribution retirement plan sponsored by an employer that allows employees to save and invest a portion of their paycheck before taxes are taken out. This page ranks the 50 largest 401(k) plans in the dataset by end-of-year total assets. Together the plans listed here hold $1.5T in aggregate assets and cover 7,211,746 participants, a mix of active employees, separated workers with remaining balances, and retirees receiving benefits.

The largest plan in this category, The Boeing Company 401(k) Retirement Plan (The Boeing Co. and Consolidated Subsidiaries, WA), reports $73.9B in assets with 139,394 participants. Within 401(k) plans, size reflects a combination of workforce scale, employer contribution rates, employee deferral rates, and long-term investment performance, not a quality rating. Larger plans often benefit from lower per-participant fees, broader investment menus, and more sophisticated administration, but participant outcomes depend on contribution behavior and investment selection. Ranking tables below link to each plan's detail page for EIN, filing status, effective date, and net income.

All figures come from Form 5500 annual returns for the 2024 plan year, filed with the DOL's EBSA and released through EFAST2. Totals reflect a single year-end snapshot and fluctuate with markets and plan activity. This page is informational only, it summarizes public regulatory filings for research and educational purposes, and is not retirement, tax, legal, or financial advice. Before relying on any figure to evaluate an employer's 401(k) plan or make retirement decisions, verify the underlying filing directly on EFAST2 and consult a qualified professional.