Methodology
Every number on this site is read out of a US government filing. On a page about one plan or one employer, that filing is a click away: a match formula opens the company’s Form 11-K on SEC EDGAR, with the sentence it was read from quoted on the page, and a fee or an asset total opens that plan’s Form 5500 as the employer submitted it to the Department of Labor. A page that combines many plans names the dataset and the form year instead, because no single filing is behind a median. Nothing here is estimated, modelled, or supplied by an employer.
Where match formulas come from: SEC Form 11-K filings
Public companies whose 401(k) plan offers employer stock must file Form 11-K with the SEC each year. In 2025, the last complete filing year, 681 companies did. For each filing we:
- enumerate new 11-Ks from EDGAR’s full-text search index, with a 10-day lookback so nothing slips between runs;
- fetch the primary document, verifying byte size against the filing index and retrying on mismatch;
- read the match formula, vesting, eligibility and auto-enrollment out of the plan description, one record per plan;
- cross-check the numbers we read against the filing’s inline-XBRL employee-benefit-plan facts (2023 EBP taxonomy); a conflict sends the record to a human review queue instead of the site;
- require a verbatim source quote for every populated field; a field with no quote is published as null, not guessed.
Coverage today is 319 companies and 385 plan records, against the 681 companies that filed an 11-K in 2025. The plan years covered by those records run from December 31, 2024 to February 28, 2026, and every page states the period its own figures cover.
Where fees and assets come from: DOL Form 5500 data
The Department of Labor publishes every Form 5500 filing as bulk CSV files, refreshed monthly. We keep large 401(k)-type plans: single-, multi- and multiple-employer plans with pension feature code 2J and at least 100 participants at the beginning of the plan year, deduplicated to the latest filing per EIN and plan number. That is 57,824 plans for form year 2024, filed by 56,422 employers, since one employer can file more than one. From Schedules H and C we compute assets, participants, plan-paid administrative cost per participant, the recordkeeper, and each plan’s fee percentile within its size cohort.
2,457 of those plans have a page of their own here, the ones whose filing carries the most people and enough computed figures to say something a reader cannot read off the filing itself. Their sponsors sit in 55 states and US territories, with 55 recordkeeper brands after name mapping. The release behind them was last modified July 28, 2026, and every plan page records that date.
The figures are computed from those bulk files, but no reader has to open a bulk file to check one. Every plan page also links that plan’s own Form 5500 as the sponsor submitted it, served by the Department of Labor, so a figure on a page and the document behind it are one click apart.
Rules every record must satisfy
No record reaches the site without satisfying these, and the pages render them.
Every fact links the document it came from
SEC facts open the filing by accession number, with the verbatim quote expandable in place. Form 5500 facts open the filing itself, served by the DOL, and print its ACK_ID, the sponsor EIN and the plan number so the same document can be found without this site.
Staleness is labeled, never hidden
“Plan year ended X, filed Y” on every page. The newest reporting period here closed 7 months ago, and the plan year most Form 5500 records report closed 21 months ago.
Admin fees are plan-paid only
We never call a plan “free” or “cheap” in absolute terms; $0 usually means the employer pays.
Missing Schedule C is missing
Rendered as “not reported in filing”, never as $0.
Silence is not absence
An 11-K that does not mention auto-enrollment is labeled “not mentioned”, not “none”.
Undisclosed stays undisclosed
Discretionary or CBA-set match rates are stated as such; we do not fill gaps from secondary sources.
Two timestamps, never conflated
Data-as-of date (from the filing) vs. page-updated date (from our build).
The scorecard on every page
Company pages and plan pages carry the same four figures in the same order: what the employer puts in per year at one standard salary, what a worker has to contribute to collect all of it, a vesting score out of 100 for how fast that money becomes theirs, and what the plan costs. Two of the four are computed rather than read straight off a filing, so the salary, the exact formula and a fully worked example on one real plan are published on the scorecard methodology page. The score measures the vesting schedule and nothing else. A plan whose filing states no schedule gets no score, and the page says so. The wait before the match starts and the year-end true-up are printed beside the score as filed terms wherever a filing states them, and neither moves the number.
How we check our own numbers
In the August 2026 round we re-read 22 filings from scratch and compared every match formula, vesting schedule and enrollment default against what this site says. Nothing disagreed: 66 facts checked, no errors. One record differed by convention rather than by fact, where a filing gives both the year’s formula and a new one starting after year end, and the site leads with the current one while keeping the old one on the page.
The company-by-company table, with the filing quote for every row, is on the accuracy audit page. It is rerun as coverage grows.
How old the data is, and why
An 11-K is due up to 180 days after the plan year ends; a Form 5500 up to 9½ months after. Bulk publication adds more lag. The site does not estimate what that adds up to, it reads it: the newest reporting period on the site today closed 7 months ago, and the plan year that more Form 5500 records report than any other closed 21 months ago, on December 31, 2024. That second figure is not the far end of the range. The plan year on 95% of the Form 5500 records ended on that date or earlier, the oldest of them on December 31, 2008, and it gains a month every month until the next annual file lands. We print the reporting period on every page.
What this data does not contain
Read this before publishing anything computed from these pages.
Large plans only, not every US 401(k) plan
Every plan here has at least 100 participants and files the full Form 5500. Smaller plans file the short Form 5500-SF, which reports far less, and they are not in this data. An average or a median you compute by adding up plan pages describes large plans, not US 401(k) plans, and the medians on fees by plan size carry the same limit.
Every figure here describes a plan year that has already closed
The newest reporting period on the site closed 7 months ago and the plan year most Form 5500 records report closed 21 months ago, so a plan that changed its match last quarter will not show it until its next filing. Nothing on this site is a current term. It is a filed one.
Fees are plan-paid only
Every fee figure counts money that left plan assets. Fees the employer pays out of its own pocket are invisible here, and so are fees netted inside a fund’s expense ratio. A low administrative cost per participant is not evidence that participants pay little.
11-K coverage is limited to employers whose plan holds company stock
Form 11-K is required only when a plan offers interests in the employer’s own securities. That excludes every private employer, every public employer whose plan holds no company stock, and every small plan. The match formulas here are therefore a slice of large listed US employers, not a sample of US employers. A company we do not cover has not been shown to lack a match; most likely it never had to file.
Some links between the two sources are inferences
An 11-K states a plan EIN only part of the time, so some links between a company and its Form 5500 record are made by matching sponsor names. 303 of the 319 companies carry a link to a Form 5500 record, and 119 of those were matched by name. A name match binds the employer, not the plan, so the linked record can cover a sibling plan of the same employer. Pages that rest on a name match say so in place.
Silence is recorded as silence
A blank field means the source does not state the value. It never means zero and it never means no. Auto-enrollment reads not mentioned when a filing says nothing, which is not the same as none. A missing Schedule C leaves the recordkeeper blank; the plan still has a recordkeeper.
What is not in scope at all
No participant-level or account-level data of any kind. No investment menu, fund lineup or fund-level expense ratios. No 403(b), 457 or defined benefit pension data. No forecasts, no ratings and no advice.
How to report an error
Write to corrections@401kmonitor.com with the page and the filing. Confirmed errors are corrected in the next build and logged. The full correction policy is on the contact page.
