Idaho 401(k) plans

Name: Idaho 401(k) plans: assets, participants and plan-paid fees
Creator: 401(k) Monitor
License: https://401kmonitor.com/licence/

259

Large 401(k) plans headquartered in Idaho are in 401(k) Monitor’s published set, holding $17.4B in total, led on headcount by Winco Foods 401(k) Plan with 24,430 active participants. Computed from DOL Form 5500 filings, plan years 2021–2024.

State means the sponsor’s address on the filing, not where employees work. The figures above read all 259 of the form-year-2024 DOL EFAST2 filings from Idaho, so they are every plan of that size filed from the state; 6 of them have a page of their own here. A plan with fewer than 100 participants files a shorter form and is not in this data at all.

6 of the biggest 401(k) plans headquartered in Idaho

The plans this site submits to search engines come first, then the rest of the ones with a page; each group is ranked by active participants, the people still building up a balance. plan years 2021–2024, DOL EFAST2 bulk data. Assets in USD. Every row links to its full fact page.
#	Plan	City	Active participants	Assets
1	Winco Foods 401(k) Plan	Boise	24,430	$289.6M
2	Micron Technology Inc. Retirement At Micron (Ram) Plan	Boise	9,878	$3.7B
3	Simplot Retirement Savings Plan	Boise	9,014	$1.6B
4	Idaho National Laboratory Employee Investment Plan	Idaho Falls	6,578	$2.5B
5	Pennant 401(k) Retirement Savings Plan	Eagle	6,390	$75.1M
6	Lamb Weston, Inc. 401(k) Plan For Plant Hourly Employees	Eagle	5,240	$253.5M

Every Idaho plan page, by size

The table above is the top of the list. These 2 pages hold the 6 published plan pages from Idaho, out of 259 filings of that kind in the data, split by how many people are in them, each ranked by active participants.

1,000 to 4,999 participants · 1 plans
5,000 or more participants · 5 plans

401(k) fees in Idaho vs the national median

Plan-paid administrative cost per participant, plan years 2021–2024 Form 5500 filings. Computed over every large plan filed from Idaho, whether or not it has a page here. The medians read only the ones whose filing reports a plan-paid cost.
Idaho medianAcross the 236 Idaho plans in our set with usable fee data.	$132.45 per participant
National medianAcross 54,782 published plans with usable fee data.	$122.17 per participant
Difference	$10.28 above the national median

Plan-paid means fees the plan itself reports on Schedule H; many employers pay providers directly, which a filing reports as $0. How to judge your own plan: are your 401(k) fees high?

Useful links

All states
Plan counts, fees and largest plans, state by state.
The largest 401(k) plans in the US
The national ranking these state tables are drawn from.
Average 401(k) fees by plan size
Fees depend on plan size more than on state.

Cite: 401(k) Monitor, “Idaho 401(k) plans: largest plans and fees”, computed from DOL EFAST2 Form 5500 bulk data, plan years 2021–2024, published set of 57,824 plans, data as of July 28, 2026.