About 401(k) Monitor
401(k) Monitor is an independent data publication. It reads official SEC and DOL retirement-plan filings and republishes the 401(k) match, vesting and fee facts they contain. A plan page or a company page links the filing it was read from; a page that combines many names the dataset and the year behind it.
Who runs this site
No advisory firm, no recordkeeper and no asset manager is behind this site. It is not affiliated with any company it covers. It sells nothing and currently runs no ads.
The site is maintained by one person, who signs as the 401(k) Monitor maintainer and publishes no name. That is a choice, not an accident: the maintainer would rather the data be checked against the filings than against a name. That is also what the pages are built to allow: a plan page links the Form 5500 the employer submitted, a company page links the Form 11-K it filed with the SEC, and both print the identifiers that find the same document without going through this site. Trusting a number here never requires trusting whoever wrote the page.
Nothing on this site is financial advice. It publishes what employers filed.
How the numbers are produced
- Match formulas, vesting and enrollment rules come from SEC Form 11-K filings, the annual report a public company must file for a 401(k) plan that offers employer stock.
- Every populated field must carry a verbatim quote from the filing; a field with no quote is published as null, not guessed.
- The numbers read from a filing are cross-checked against its inline-XBRL facts; a conflict sends the record to human review instead of the site.
- Assets, participants, plan-paid fees and recordkeepers are computed from DOL Form 5500 bulk data.
- Both sources are re-read as they publish, and the updates page dates the newest filing this site has read from each of them.
The site reads 57,824 large plans filed by 56,422 employers, and publishes a page of its own for 2,457 of those plans; every figure on every page is computed over all of them. Of those employers, 319 also file an SEC Form 11-K, which is where a match formula and a vesting schedule can be read word for word. The rest are read on what the Form 5500 reports: contributions, plan-paid fees and the recordkeeper.
Form 5500 in this detail is filed only by plans with 100 participants or more. Smaller plans file a short form that reports far less, so they are not in this data and no page here covers them.
The rules every record must satisfy, and the error rate measured on our own output, are on the methodology page. When each source last moved is on the updates page.
Every company page, plan page and stats page shows its figures next to the filing they were read from, so a number you are reading can be checked against the source. Quoting figures with credit and a link is welcome, and the terms are on the licence page.
What this domain was before 2026
This publication started in August 2026. The address is much older, it was other things first, and none of them have anything to do with this one.
2001 to 2002: a plan-sponsor consultancy
The address served the site of Hilger Associates, which advised 401(k) plan sponsors on choosing and monitoring their plan providers. Capture of 18 April 2001 ↗
2003 to 2005: a paid market-timing subscription
Under different management the name was used for a subscription service that sent email alerts telling subscribers when to move money in and out of their 401(k) accounts. It sold a product. This site sells nothing and gives no signals. Capture of 12 December 2003 ↗
2006 to 2023: nothing published
No site was served here. Captures through this period return a web hosting control panel’s default page, which is what an address with nothing behind it answers with. Capture of 28 May 2019 ↗
2024: listed for sale
The address was parked on a domain marketplace with a page reading that the domain name was for sale. Capture of 22 August 2024 ↗
August 2026 onward: this publication
The domain was bought on the open market and this site was published on it. There is no continuity of any kind with what came before: no page, no text, no subscriber, no data and no author carried over, and nothing that was published here before 2026 is republished here now. The archived pages above are linked so the break can be seen rather than asserted.
Checked against the Internet Archive on 1 September 2026, which holds 397 captures of this address, the first dated 18 April 2001.
Why this site exists
The match formula, the vesting schedule and the plan-paid fees of a large 401(k) plan are public information. Employers are required to file them with the SEC and the Department of Labor. In practice they are unreadable: the facts sit in audit exhibits and bulk CSV files that almost no plan participant will ever open.
This site exists to make them readable.
How to report an error
Write to corrections@401kmonitor.com with the page URL and the point of disagreement. Every report is checked against the government filing the page cites. A confirmed error is fixed in the next build of the site, usually within days, and the correction is noted on the affected page. A report the filing does not support gets a reply saying what the filing says. For anything that is not an error report, the address and what to expect are on the contact page.
