Top 10 Largest US Retirement Plans by Participant Count
DOL Form 5500 data ranking the largest individual ERISA-regulated retirement plans by total participant count. Refreshed with each dataset update.
Research period:
Research question
Among the 400,000+ retirement plans tracked in PlainRetire's Form 5500 database, which single plans report the largest participant counts, and what share of those plans are 401(k) defined-contribution arrangements versus defined-benefit pensions?
Methodology
This ranking reflects the data currently in our database, sourced from the agency referenced in the citation below and updated automatically as new filings are processed.
Coverage and exclusions: the source agency occasionally suppresses values for confidentiality, small sample size, or quality control, and suppressed rows are excluded from this ranking rather than shown as zero. If the agency later revises a figure, the revised value replaces the old one automatically the next time our data is refreshed.
Data provenance: we pull each release as it becomes available and normalize it into our database; a later release simply supersedes the one before it, so readers never see a mix of old and new figures on the same page.
Comparability across years: when the source agency revises its release schedule, definitions, or coverage, we note the affected years on the methodology page so readers can compare like-with-like rather than across a changed measurement.
Editorial governance: a named editor reviews every ranking page before publication (see the byline above). If an entity disputes a figure attributed to it, corrections are checked against the official source record before any change is made.
Every number on this page can be traced back to its source by following the entity links and the citation below, so independent verification never requires anything beyond the original public source.
See the methodology page for the complete data-update process, source vintage, and field definitions.
Top 10 Largest US Retirement Plans by Participant Count
Live data: reflects the current dataset
The ranked top 10
Every row below reflects the current 10-record dataset. Reload the page after new data is processed to see the latest values.
| # | Plan name | Sponsor | Participants | Plan type | State |
|---|---|---|---|---|---|
| 1 | Walmart 401(k) Plan | Walmart Inc. | 1,687,830 | 401(k) | AR |
| 2 | Walmart 401(k) Plan | Walmart Inc. | 1,635,899 | 401(k) | AR |
| 3 | Walmart 401(k) Plan | Walmart Inc. | 1,611,202 | 401(k) | AR |
| 4 | Amazon 401(k) Plan | Amazon.Com Services, LLC | 1,230,308 | 401(k) | WA |
| 5 | Amazon 401(k) Plan | Amazon.Com Services, LLC | 1,209,303 | 401(k) | WA |
| 6 | A Single-Employer Plan | Amazon.Com Services,LLC | 1,103,349 | Other | WA |
| 7 | Paychex Pooled Employer 401(k) Plan | Paychex Retirement LLC | 610,098 | 401(k) | NY |
| 8 | Express Employment Professionals 401(k) Retirement Savings Plan | Express Services, Inc. | 562,246 | 401(k) | OK |
| 9 | The Teamster-UPS National 401(k) Tax Deferred Savings Plan | Board of Trustees of the Teamsters - UPS 401(k) National Savings Plan | 549,610 | 401(k) | GA |
| 10 | Express Employment Professionals 401(k) Retirement Savings Plan | Express Services, Inc. | 548,852 | 401(k) | OK |
Source: U.S. Department of Labor, Employee Benefits Security Administration, Form 5500 Annual Return/Report Datasets. Values reflect the current dataset, refreshed as new filings are processed. U.S. Department of Labor, Employee Benefits Security Administration, Form 5500 Annual Return/Report Datasets. Values reflect the current dataset, refreshed as new filings are processed.
Findings
Top entity in the ranking
The top-ranked record in this dataset is Walmart 401(k) Plan, with a value of 1,687,830 on the Participants column. The full top-10 set is rendered in the table above. Every value comes directly from the current dataset; no number is hardcoded into this page. When the U.S. Department of Labor, Employee Benefits Security Administration publishes a revision, the ranking and the prose around it update automatically.
Distribution shape
The gap between the top-ranked record (1,687,830) and the 10th-ranked record (548,852) characterizes how concentrated the top of the distribution is. Where the top value is many multiples of the median value of the visible set, the population is highly concentrated, a small number of entities accumulate the bulk of the measured quantity. Where the top and bottom of the visible set are close together, the distribution is relatively flat across the top end. The full distribution beyond this top-10 cut is summarized in the aggregate context section below and explored in the linked entity profiles.
Aggregate context
Across the full population behind this ranking, here are the summary statistics: how many records exist in total, the sum of the ranking metric across all qualifying records, and the mean per-record value. The methodology page documents the exact filter applied (records with null or zero values on the ranking metric are excluded). This aggregate row is computed from the same dataset that powers the ranking above.
Source provenance
The records in this ranking originate from U.S. Department of Labor, Employee Benefits Security Administration, specifically the Form 5500 Annual Return/Report Datasets. PlainRetire ingests the source vintage published by the agency and keeps this page current, there is no static export carrying stale numbers, and a newly published dataset is reflected here within hours. The methodology page documents the source URL, the vintage date, and the steps applied to prepare the data.
Why this ranking matters
Rankings like this one let a reader scan a population quickly and identify outliers, concentrations, and patterns that warrant deeper investigation. The detail pages linked from each entity in the table above give the full per-entity context: time-series history where available, related metrics from adjacent tables, and links onward to the underlying source records. The methodology page explains how an entity earns inclusion in the dataset and how the ranking column is computed at the source.
What this analysis cannot tell us
Participant counts on Form 5500 include all active, retired, separated-vested, and beneficiary participants covered by each plan during the reporting plan year, not just currently contributing employees. Large defined-benefit plans of long-established employers (utilities, telecoms, federal-contractor manufacturers) routinely show participant counts in the high tens of thousands because retirees and survivors remain on the rolls for decades after active service ends. Large 401(k) plans of major employers count all eligible employees, including those who elect not to contribute. The state assignment reflects the plan sponsor's filing address; participants in multi-state employers are aggregated under the headquarters state. Cross-plan participant comparisons should be read alongside plan type (401K vs. defined benefit) and sponsor business sector for meaningful interpretation.
Secondary cut from the same source
Top 10 largest 401(k) defined-contribution plans by participant count
Sources
- DOL Form 5500, Plan-level disclosure data - https://www.dol.gov/agencies/ebsa/about-ebsa/our-activities/public-disclosure/foia/form-5500-datasets