Form 5500 Search: Look Up Your Employer's Health Plan

Costco's 2024 annual report for a plan called Costco Employee Benefits Program, plan number 510, checks exactly one box on line 9a of the Form 5500: General assets of the sponsor. Line 9b, the same. The welfare codes typed above those boxes are 4A, 4D and 4E, which in the Labor Department's code list mean health, dental and vision. No insurance box is checked, and no Schedule A is attached. The plan reported 192,501 participants at the start of the year.

That is what a self-funded health plan looks like in the government's own records, and anyone can pull it up without an account, a fee, or a conversation with HR. I downloaded that filing, and the other Costco welfare filings used below, from the Department of Labor's public Form 5500 Search on 19 September 2026. I picked Costco only because it is large, files several separate health and welfare plans, and makes a clean teaching example. Nothing here is a claim about how any Costco employee's claim should be handled.

Why bother? Because whether your plan is self-funded or fully insured decides which regulator can touch it and, usually, which external review process your appeal ends up in. The companion page on self-funded vs fully insured plans explains what changes. This page is the procedure for looking it up yourself, one screen at a time, including the part most guides skip: what it means when the search comes back empty.

Every line number below comes from the 2025 Instructions for Form 5500 or from the search tool's own help page, both read on the date above.

Two numbers to find before you type anything

You can search by company name, and for a household-name employer that works. For everyone else, names are a mess. The filing might be under the parent company, a holding company, "and Subsidiaries," a former name, or an abbreviation someone chose in 2011 and has been required to reuse ever since (the instructions tell filers to keep using the same plan name or abbreviation on every future return). Two numbers cut through all of that.

The EIN. This is the employer's nine-digit federal Employer Identification Number, and it goes on line 2b of the Form 5500. You already have it: it is printed in box b of your W-2. If your paycheck comes from a staffing company or a professional employer organization, the W-2 EIN may belong to that company rather than the business you report to every day, and the health plan could be sponsored by either one. Try both.

The plan number (PN). Every ERISA plan carries a three-digit number assigned by its sponsor, entered on line 1b. The EIN plus the PN is how the IRS, DOL and PBGC tell one plan from another, a 12-digit identifier in the instructions' words. Your Summary Plan Description has to print both: 29 CFR 2520.102-3(c) requires "the employer identification number (EIN) assigned by the Internal Revenue Service to the plan sponsor and the plan number assigned by the plan sponsor." Look near the back of the SPD, usually in a block with the plan year and the name of the plan administrator.

One detail makes the PN easy to recognize. The instructions tell filers to number plans that provide only welfare benefits starting at 501, and pension plans starting at 001. A 401(k) will usually be 001 or 002. Health, dental, disability and cafeteria plans will be 501 or above. Costco's search results show exactly that split: 002 and 005 for the retirement plans, 501, 510, 511, 512 and 513 for the welfare plans.

No SPD yet? Search by EIN anyway and read the plan names. You will usually be able to tell which one is the medical plan, and the PN you find becomes the thing you cite when you write to ask for the SPD.

Running the search on EFAST2

The tool lives at efast.dol.gov/5500Search. It displays what plan administrators filed through EFAST2, the all-electronic system that has taken Form 5500 filings since the turn of 2010; the oldest entries in its index are dated December 31, 2009. Keep one thing in mind from the start: a posted filing is what the plan administrator reported and signed, not a government finding.

Step by step:

1. Open the drop-down next to the search box. It defaults to Plan Name. Switch it to EIN, Plan Sponsor, or AckID (the acknowledgement ID EFAST assigns to each submission). The help page confirms that the EIN works with or without the hyphen, so 91-1223280 and 911223280 return the same thing. For Costco's EIN, the search returned 115 filings when I ran it.
2. If you must search by name, use the operators. Searches are case insensitive and match all the words you type in any order. An asterisk widens a word (widget* finds widgeting), a leading hyphen excludes one (-retirement), and double quotes force an exact phrase. Searching acme -401k -retirement -pension strips out most of the pension plans in one go.
3. Narrow with filters if the list is long. Show Filters opens Welfare Benefit Types, Participants, Plan Years, States, Zip Code and more. The Welfare Benefit Types filter maps to the characteristic codes; ticking the health code leaves only plans that reported providing health benefits. The help page's table says those codes sit on "line 9b." That is out of date: on the 2024 and 2025 forms the welfare codes are on line 8b, and 9b is the benefit-arrangement boxes covered below.
4. Sort by plan year by clicking the column heading.
5. Download the filing. Click the arrow at the left of the row. The help page says a ZIP archive downloads with the PDF inside. The PDF is a filled-in facsimile of the form rather than a scan, and on the files I opened, copying text out of it returned template placeholder text instead of the entered values. Read it on screen.

The search tool shows at most 5,000 results per query. If you hit that, you searched too broadly. If you believe a filing exists and cannot find it, the help page lists the EFAST2 Help Desk at 866-463-3278.

Picking the right row out of several

Large employers do not file one Form 5500. They file one per plan, and they are allowed to divide their benefits into plans however they like. The instructions say so plainly: a sponsor could create one plan providing medical, dental and vision, or two plans, or three, and you have to look at the governing documents to know which. So you may be looking at a list like this one, the 2024 plan-year welfare filings under Costco's EIN:

Three things trip people up here.

The plan-year label is the year the plan year began. The 2024 filings for plans 501, 510 and 512 each carry the same attached statement: the "2024" plan year ran from September 2, 2024 to August 31, 2025. If your employer runs a fiscal plan year, a denial from March 2025 may belong to the filing labeled 2024, not 2025. And do not assume every plan of one employer shares a year: Costco's cafeteria plan, 511, reports on a calendar year. Check the dates printed at the top of page 1 of the filing you are reading.

The newest year is usually missing. A 5500 is due by the last day of the seventh calendar month after the plan year ends, and Form 5558 buys up to two and a half months more. For a calendar-year plan, the 2025 report can arrive as late as mid-October 2026. Costco's 2024 filings for plans 501, 510 and 512 were received on June 15, 2026, and none of its 2025 health filings were posted when I searched. If your denial is recent, the filing for last year is often the best you can get, and funding arrangements do not usually flip from year to year. That word usually is the reason you still need the SPD.

Only the latest version of each year shows. Since March 28, 2023, the search tool displays only the most recent filing for each plan year, so an amended return replaces the original in the list. The 2024 filings for plans 501, 510 and 512 are all marked as amended returns on page 1. You are seeing the corrected versions, which are the ones you want.

The participant counts in that table do not include dependents. Line 5 and line 6 count employees, former employees on COBRA, and similar people, and the instructions say covered dependents are not counted as participants. So do not compare them with a headcount that includes spouses and children.

Page 2: the four boxes that answer the funding question

Scroll to page 2 of the Form 5500. Everything you need for a first answer sits in a band roughly two inches tall.

Line 8b, welfare feature codes. Two-character codes from the list in the instructions. The ones you will see most:

If a plan's line 8b has no 4A, it is not your medical plan, whatever it is named. Costco's plan 512 is called a Vision and Prescription Drug Program. Prescription drugs sit inside medical coverage for most people, so read the codes before you rule a plan in or out.

Line 9a, plan funding arrangement, and line 9b, plan benefit arrangement. Four boxes each: Insurance; Code section 412(e)(3) insurance contracts (a pension item you can ignore); Trust; and General assets of the sponsor. The instructions define them this way:

• Insurance means the plan has an account, contract, or policy with an insurance company or similar organization, "such as Blue Cross Blue Shield, or a health maintenance organization." Then the sentence that makes this whole exercise work: "Do not check 'insurance' if the sole function of the insurance company was to provide administrative services."
• Trust means a fund or account holding plan assets other than an insurance policy. Some self-funded plans run employee contributions through a trust, often called a VEBA.
• General assets of the sponsor means the plan had no assets, or its assets were mixed in with the employer's own money before benefits were paid.

Line 10b(3), the Schedule A count. A checked box with a number beside it tells you how many Schedule A insurance attachments follow. The instructions require at least one Schedule A whenever 9a(1) or 9b(1) is checked, and the Schedule A instructions say not to file one for "an Administrative Services Only (ASO) contract."

Put together:

Costco's plan 510 is the first row. Its plan 501 is the third, which is where it gets instructive.

Schedule A: whose contract, and for how many people

Plan 501 lists welfare codes 4A, 4B, 4D, 4F, 4H, 4L and 4Q, checks both Insurance and General assets of the sponsor on 9a and 9b, and attaches 10 Schedules A. Each one names a carrier in Part I, gives the carrier's EIN and NAIC company code, a contract number, and "approximate number of persons covered at end of policy or contract year." Part III, line 8, then has checkboxes for what the contract covers: health, dental, vision, life, temporary disability, long-term disability, supplemental unemployment, prescription drug, stop loss, HMO, PPO, indemnity, or other.

Reading all ten in order:

• Seven are life, accident, or disability contracts: Hartford (business travel accident), Provident Life and Accident (long-term disability), four Unum Life Insurance Company of America contracts (temporary disability, long-term disability, life), and First Unum Life Insurance Company (other, described as New York disability benefits law coverage).
• One is Aetna International, 640 persons, marked Other with a description referring to a world traveler benefit.
• Two check Health. Hawaii Medical Service Association, 4,494 persons, health plus HMO contract. Triple-S Salud, the Puerto Rico carrier, 1,283 persons, health, dental, prescription drug and PPO, plus Other described as major medical, transplant and teleconsultation.

So the one filing whose line 8b includes a health code shows insured medical contracts covering about 5,800 people, in Hawaii and Puerto Rico, against 217,327 participants at the start of the year. The persons-covered figure and the participant count are not measured the same way, so that comparison is rough. But the shape is clear: nothing on the filing shows an insurance policy standing behind medical claims for everyone else, and the box that describes paying from the employer's own assets is checked.

That is the practical lesson from a mixed filing. The same plan can be insured for one group of employees and self-funded for another. Someone in Honolulu and someone in Ohio can hold ID cards from the same employer under different funding and therefore different state-law protection. On a mixed filing, the question is not "is the plan insured" but "is there a Schedule A covering health for people where I work."

Two things that look like insurance on a Schedule A and are not:

Stop-loss. Part III has a box for Stop loss (large deductible), and the instructions say to report a stop-loss policy there when it is an asset of the plan. They add that employers often buy stop-loss with the employer as the insured, paid entirely out of the employer's own money, and that those contracts "generally are not plan assets and are not reportable on Schedule A." Either way, stop-loss protects the employer from a bad year. It does not insure your claim. A Schedule A that checks only stop-loss is a sign of a self-funded plan, not an insured one.

Non-medical contracts. A plan that checks Insurance on line 9a because it buys life or disability insurance can still be self-funded for medical. Plan 501 is exactly that for most of its participants. Always match the Part III checkboxes to the benefit you were denied.

One more clue sits on every Schedule A: the NAIC code in Part I, line 1(c). It identifies the insurance company in the National Association of Insurance Commissioners' system, which is how state insurance departments look carriers up. If you end up filing a state complaint against an insured plan, that code and the contract number on line 1(d) let the department find the right policy quickly.

When the search returns nothing

An empty result is common, and it is rarely the finding people assume. Before concluding anything, work through these in order.

The plan may be too small to file. Under 29 CFR 2520.104-20, a welfare plan that had fewer than 100 participants at the beginning of the plan year is exempt from filing an annual report if its benefits are paid "solely from the general assets of the employer," or provided "exclusively through insurance contracts or policies," or both, provided employee contributions and refunds are handled within the regulation's time limits and the plan is not an arrangement that must file Form M-1 (a multiple employer welfare arrangement). Read that list again: it includes both small insured plans and small self-funded plans paid from the employer's bank account. So for an employer with, say, 60 people on the health plan, no filing tells you nothing about funding. It is the expected result either way.

The plan may not be an ERISA plan. The instructions list governmental plans and church plans among those that do not file. City, county, school district and state employees will not find their health plan here, and neither will many employees of churches and church-run organizations.

The filing may be under someone else. A plan that participates in a group insurance arrangement may have its report filed by the arrangement on its behalf (29 CFR 2520.104-43). A staffing company or PEO may sponsor the plan. A parent company may file under its own EIN. Try every EIN on your W-2s for the last two years, and the parent company's name.

The newest year may not be due yet. See the timing above.

You may be searching the wrong name. If you searched by name, search again by EIN. If you searched by EIN, try the sponsor name with an asterisk.

If you run every step and still find nothing, write down what you searched and when, and move on to the SPD. "I could not find a filing" is a note for your file. It is not evidence that the plan failed to file, and I would not put that claim in an appeal or a complaint.

What the filing cannot settle, and the request it sets up

The Form 5500 is what the plan administrator reported about a past plan year. It carries no coverage terms, no exclusion language, and no appeal rights. It can be amended. And the search search tool posts what was filed without vouching for it. So treat what you found as a strong working answer, not as proof you can quote in an appeal.

The document you quote is the Summary Plan Description. When an insurance company finances or administers a group health plan, the SPD has to name it and say whether and to what extent benefits are guaranteed under its policy (29 CFR 2520.102-3(q)). When the SPD and the 5500 disagree, that disagreement is itself useful: it is a specific question you can put to the plan administrator in writing. For how the SPD fits with the other plan documents, see SPD vs SBC: which plan document governs.

The filing does make that written request much sharper. Instead of "please send my plan documents," you can write:

Under ERISA section 104(b)(4), please furnish the latest summary plan description, any summaries of material modifications, the latest annual report, and the instruments under which the plan is established or operated, for the [plan name exactly as filed], plan number [PN], sponsor EIN [EIN], for the plan year that includes [date of service].

Naming the plan the way it appears on line 1a, with its PN, leaves no room for HR to send the wrong booklet or the dental plan's SPD. Asking for "the latest annual report" gets you the same Form 5500 with the schedules, straight from the administrator. One caveat from the small-plan regulation: a plan exempt from filing under 2520.104-20 is also not required to furnish an annual report on request, though it still must provide the SPD.

Once you know which funding answer applies, it decides the next step on the appeal track: whether your external review goes through a state process or the federal one. The internal appeal vs external review page covers the deadlines on each. Put the plan name, PN, EIN, the plan year you looked at, and the line 9a boxes on one sheet in your claim file, with the date you searched. If a denial is live right now, send the section 104(b)(4) letter today, because the 30-day clock for the administrator's response only starts when your written request arrives.