Form 5500 ranking
Largest 401(k) Plans in America
The biggest 401(k) plans ranked by total assets under management.
Data updated 2026-05-15
- $72.2B
- #1 401(k) Plan
- 50
- Ranked
- $1.3T
- Combined total assets
The ranking in one line
The Boeing Company 401(k) Retirement Plan leads with $72.2B in total assets; the 50 401(k) plans ranked here hold $1.3T combined.
- $72.2B
- #1 - The Boeing Company 401(k) …
- 50
- 401(k) plans ranked
- $1.3T
- combined total assets
What This Ranking Tells Us
These are America's largest 401(k) defined contribution plans. Unlike pensions, 401(k) plans place investment decisions and risk with participants, employees choose from a menu of funds and their retirement income depends on how well those investments perform. The largest 401(k) plans belong to major corporations with large workforces and generous matching programs. Boeing, Microsoft, and major banks lead because they combine high employee counts with above-average compensation driving larger contribution amounts.
How to Read the Largest 401(k) Plans in America Ranking
This page ranks 50 401(k) plan records by total assets, from The Boeing Company 401(k) Retirement Plan at the top ($72.2B) through UPS 401(k) Savings Plan at #50 ($13.1B). The underlying dataset is drawn from the Department of Labor, Form 5500 Annual Return/Report for the 2023 plan year. Each ranked entry links to a detail page with the full set of Form 5500 fields, plan type, sponsor EIN, state, participants, net assets, net income, and prior-year history where available.
These are America's largest 401(k) defined contribution plans. Unlike pensions, 401(k) plans place investment decisions and risk with participants, employees choose from a menu of funds and their retirement income depends on how well those investments perform. The largest 401(k) plans belong to major corporations with large workforces and generous matching programs. Boeing, Microsoft, and major banks lead because they combine high employee counts with above-average compensation driving larger contribution amounts.
Rankings based on a single metric can be misleading in isolation - "Total Assets" captures one dimension of a plan's profile and does not measure participant outcomes, fees, investment options, or funding health. Year-to-year movement in this ranking reflects market performance, workforce changes, plan mergers, and filing timing as much as plan quality. This page is informational only, summarizing public DOL disclosures for research and educational purposes, and is not retirement, tax, legal, or financial advice. Before relying on any ranking to evaluate an employer's plan or make retirement decisions, verify the underlying filing on EFAST2 and consult a qualified professional.
Source: Department of Labor, Form 5500 Annual Return/Report.
Frequently Asked Questions
How does a 401(k) differ from a pension?
In a 401(k), employees contribute from their paycheck (up to $24,500 in 2026), the employer may match a portion, and the employee chooses investments from a menu. The retirement benefit depends on total contributions plus investment growth. In a pension, the employer promises a fixed benefit and bears all investment risk.
Do employees in larger 401(k) plans do better?
Often yes. Larger plans negotiate lower fund fees (sometimes 0.01-0.10% versus 0.50%+ for small plans), offer more investment options, and often have better financial education programs. Fee differences compound dramatically over a 30-year career, 0.5% lower fees can mean 10-15% more retirement savings.
Nearby Rankings
Other leaderboards cut from the same Form 5500 dataset, ranked by different metrics.
Source: Department of Labor, Form 5500 Annual Return/Report. Rankings rebuilt from the publicly released 2023 plan-year file.
Source: DOL EFAST2 filing system (efast.dol.gov) - original Form 5500 filings retrievable by plan sponsor EIN or plan name.
Read our methodology - how this data is sourced, computed, and verified.
How Plan Rankings Are Constructed
Ranking retirement plans is more subtle than ranking, say, restaurants or stocks. A "largest" plan is unambiguous when measured by participant count or asset total, both are reported in Form 5500 and audited by an independent accountant once a plan crosses the 100-participant threshold. But a "best" plan is contextual: the right benchmark for a multi-employer pension fund is different from the right benchmark for a single-employer 401(k), and both are different from the benchmark for an ESOP. PlainRetire's ranking pages stick to clearly defined, source-derived metrics, participant counts, plan assets, net contribution, employer contribution as a share of pay, year-over-year asset growth, and surface each metric on its own page so readers can decide which framing is relevant for their question.
Each ranking includes the underlying source (Form 5500 schedule and line item), the plan-year vintage, and a footnote when an aggregate excludes plans with incomplete or amended filings. Where a plan has filed multiple amendments, a sometimes-routine but sometimes-meaningful signal, the ranking uses the most recent accepted filing and notes the amendment count on the plan detail page. This approach lets readers see who is at the top of a particular ladder without conflating different scales of "size" or "growth."
Methodology and Limitations
Rankings are computed against the most recent annual dataset released by the Department of Labor. New plans, terminations, and significant amendments will not appear until the next annual release, which has roughly a seven-month publication lag from plan year end. Plans that file Form 5500-EZ (single-participant plans) are not included in the public datasets and therefore do not appear in PlainRetire rankings. International plans, government plans, and church plans (which are exempt from Title I of ERISA) are similarly outside the dataset and outside these rankings. When evaluating a ranking, consider the universe being compared: a national ranking of 401(k) sponsors will be dominated by Fortune 500 employers, while a state-level ranking will surface regionally significant plans that don't appear in the national list.
Asset and participant counts are reported by the plan sponsor and certified by an auditor for plans above 100 participants. Smaller plans rely on plan-sponsor attestation. Both are subject to standard data-quality caveats: corrections appear as amended filings in subsequent years, and PlainRetire reflects amendments as soon as DOL releases updated datasets.