State retirement profile · Form 5500

Retirement Plans in Idaho

Employer-sponsored 401(k), pension, and other retirement plans headquartered in Idaho, drawn from DOL Form 5500 filings (plan year 2024).

Data updated 2026-05-15

720
Plans
$24.7B
Total assets
#41
By assets

The state in one line

Idaho hosts 720 employer-sponsored retirement plans holding $24.7B for 248,987 participants, the 41st-largest state by plan assets.

$24.7B
total plan assets
720
employer plans
$99,058
avg assets per participant
85%
of plans are 401(k)s
Total Plans
720
401(k) Plans
609
Participants
248,987
Total Assets
$24.7B

What the Form 5500 Data Shows for Idaho

Idaho: 720 employer-sponsored plans (609 401(k)), $24.7B aggregate assets, 248,987 participants. Average plan: $34M; largest is Winco Employee Stock Ownership Plan at $5.0B. DOL Form 5500 methodology + HQ-vs-residence caveats →

A state total like this counts every plan whose sponsor lists a headquarters address in the state on its Form 5500 filing, so the figure reflects where employers are based rather than where their workers live or where the money is ultimately invested. A handful of very large sponsors, a national retailer, a bank, a multi-employer union fund, can dominate a single state's asset total, which is why the average plan size and the largest-plan name matter as much as the headline number. Smaller plans, those with fewer than one hundred participants, file a simplified schedule and are exempt from independent audit, so part of any state total rests on sponsor attestation rather than auditor confirmation. Treat these aggregates as a structural picture of the state's private retirement economy, not as a measure of any single worker's benefit or account.

Largest Plans in Idaho

# Plan Name Type Participants Total Assets
1 Winco Employee Stock Ownership Plan ESOP 17,054 $5.0B
2 Micron Technology Inc. Retirement at Micron (Ram) Plan 401(k) 8,598 $3.7B
3 Simplot Retirement Savings Plan 401(k) 9,012 $1.6B
4 St. Lukes Health System Matched 403b Plan IRA-Based 17,370 $1.1B
5 Retirement Plan of Idaho Power Company Defined Benefit (Pension) 2,113 $971M
6 Idaho Power Company Employee Savings Plan Profit Sharing 2,119 $890M
7 St. Luke's Health System Performance Incentive and 401(a) Matching Plan 401(k) 17,370 $770M
8 Boise Cascade Company Savings Plan 401(k) 3,902 $740M
9 Power Profit Sharing 401(k) Plan 401(k) 3,637 $592M
10 Lamb Weston, Inc. 401(k) Plan for Salaried and Hourly Employees 401(k) 2,174 $444M
11 Glanbia Companies 401(k) Plan 401(k) 3,530 $336M
12 Stellar Industries, Inc. Employee Stock Ownership Plan Other 774 $331M
13 Winco Foods 401(k) Plan 401(k) 19,177 $290M
14 Woodgrain Millwork, Inc. Employee Savings Plan and Trust 401(k) 4,449 $272M
15 Norco, Inc. Employee Stock Ownership Plan 401(k) 1,381 $269M
16 Lamb Weston, Inc. 401(k) Plan for Plant Hourly Employees 401(k) 5,541 $254M
17 Blue Cross of Idaho Health Service, Inc. 401(k) Plan 401(k) 1,504 $234M
18 Shaws Supermarkets, Inc. Pension Plan for Union Employees Other 5,378 $230M
19 Terteling Employees' Profit Sharing and Thrift Savings Plan 401(k) 1,343 $183M
20 Hecla Mining Company Capital Accumulation Plan 401(k) 747 $163M
21 Boise Cascade Company Hourly Savings Plan 401(k) 2,114 $146M
22 St. Luke's Health System Basic Pension Plan Defined Benefit (Pension) 217 $144M
23 Melaleuca, Inc. 401(k) Savings Plan and Trust 401(k) 2,232 $140M
24 Idaho Forest Group LLC 401(k) Plan 401(k) 1,321 $119M
25 Hecla Mining Company Restated Retirement Plan Defined Benefit (Pension) 536 $117M

Nearby States by Retirement Plan Footprint

States ranked adjacent to Idaho by total retirement plan assets.

Compare Idaho side-by-side with 3 peer states →

Frequently Asked Questions

How many retirement plans are in Idaho? ▼
Idaho has 720 employer-sponsored retirement plans as reported in 2024 DOL Form 5500 filings, including 609 401(k) plans.
What are the total retirement plan assets in Idaho? ▼
Retirement plans in Idaho hold $24.7B in total assets, covering 248,987 participants. The average plan holds $34M in assets.
What is the largest retirement plan in Idaho? ▼
The largest retirement plan in Idaho is Winco Employee Stock Ownership Plan with $5.0B in total assets and 17,054 participants.
How does Idaho compare to other states for retirement plans? ▼
You can compare Idaho's retirement plan statistics against all 50 states on the States page. Rankings are based on total assets, plan count, and participant coverage from DOL Form 5500 data.

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Understanding Form 5500

Source: U.S. Department of Labor, EBSA Form 5500 public disclosure dataset. Shows the top 25 plans by total assets headquartered in Idaho, out of 122,942 ERISA-covered plans nationally. Plan year 2024.

Source: DOL EFAST2 filing system (efast.dol.gov) - state is the plan sponsor's headquarters state as recorded on the Form 5500 filing.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from U.S. Department of Labor Form 5500 filings (EBSA). See our methodology for details.

Why Form 5500 Data Matters for Retirement Planning

Form 5500 is the annual return that virtually every private-sector retirement plan in the United States files with the Department of Labor. The filing covers funding, participant counts, plan investments, fees, service providers, and corrective contributions. Because the data is collected for regulatory oversight rather than marketing, it is one of the most consistent windows into the retirement economy: the same questions are asked of plans across all industries and all states, year after year. That consistency makes it possible to compare plans, sponsors, and markets on equal footing, a kind of comparability that voluntary survey data and vendor brochures cannot provide.

PlainRetire reorganizes the Form 5500 universe so a participant, employer, or analyst can ask everyday questions of the dataset without reading thousands of pages of agency documentation. Browsing by state surfaces concentration patterns: where pension assets sit, which states host the largest 401(k) sponsors, where retirement coverage trails the national average. Browsing by industry reveals the structural difference between sectors that historically relied on defined-benefit pensions and sectors that adopted defined-contribution plans early. Browsing by plan size highlights both the largest sponsors, typically Fortune 500 employers and multi-employer Taft–Hartley funds, and the long tail of small plans that collectively cover millions of workers.

What This Hub Page Aggregates

Each hub page on PlainRetire is a navigable index into the underlying database. The page shows summary counts, the most recent Form 5500 vintage, and direct links to individual plan detail pages. Detail pages carry the canonical filings, schedules where applicable, and audit trail back to the DOL's EFAST2 disclosure portal. Where the underlying dataset supports it, hub pages also expose key aggregates: total participant counts, aggregate assets, plan-type breakdowns (401(k), pension, profit-sharing, ESOP), and changes over the most recent reporting period.

Plan data is updated as DOL releases new annual Form 5500 datasets. Filings have a roughly seven-month lag from plan year end, so the most recent vintage typically reflects the previous full calendar year. This lag is inherent to the disclosure regime, plans are given time to gather audit reports and service-provider statements, and PlainRetire reflects the timing transparently rather than backfilling estimates.

Reading the Data With Appropriate Caveats

Aggregate numbers are useful for trend-spotting and structural comparison; they are less useful for decisions about a specific plan. The participant count for a state, for instance, includes both very large plans (which dominate the total) and very small plans (which influence median but not mean). When evaluating a specific employer's plan, drill into the plan detail page and consider plan-type, asset-mix, fee structure, and audit history, these details are flattened in any hub-level aggregate. Where regulatory updates change the categorization of a plan, PlainRetire preserves the historical filing alongside the most recent one so longitudinal analyses remain valid.