Idaho 401(k) plans
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. Our published set covers 57,824 of the 57,824 large plans in the form-year-2024 DOL EFAST2 bulk data, so this is the largest-plan end of Idaho, not a census of it.
10 of the biggest 401(k) plans headquartered in Idaho
| # | 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 |
| 7 | Woodgrain Millwork, Inc. Employee Savings Plan And Trust | Fruitland | 4,444 | $271.8M |
| 8 | The Jackson Companies 401(k) Profit Sharing Plan | Meridian | 4,284 | $50.7M |
| 9 | Boise Cascade Company Savings Plan | Boise | 4,101 | $740.4M |
| 10 | Glanbia Companies 401(k) Plan | Twin Falls | 4,019 | $336.1M |
Every Idaho plan, by size
The table above is the top of the list. These 4 pages hold all 259 plans on file from Idaho, split by how many people are in them, each ranked by active participants.
- 100 to 499 participants · 185 plans
- 500 to 999 participants · 28 plans
- 1,000 to 4,999 participants · 39 plans
- 5,000 or more participants · 7 plans
401(k) fees in Idaho vs the national median
| Idaho medianAcross the 236 Idaho plans in our set with usable fee data. | $132.45 per participant |
|---|---|
| National medianAcross 54,783 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.