401(k) · DOL Form 5500 · 2024

Costco Wholesale Corporation 401(k) Plan

Data updated 2026-07-24

$41.0B
Total assets: 202,468
Participants: 100th
Percentile by assets: $202,587
Avg per participant

Official DOL plan name: Costco 401(k) Retirement Plan · Sponsored by Costco Wholesale Corporation · Washington · Retail Trade

$41.0B in assets, 202,468 participants

Costco Wholesale Corporation's Costco 401(k) Retirement Plan reported $41.0B in total assets and 202,468 participants in its 2024 DOL Form 5500 filing, ranking in the 100th percentile by assets among filed plans. Figures are as reported by the plan sponsor to the Department of Labor, not audited or endorsed by PlainRetire.

100th percentile by assets (of 116,472 plans)

Coverage in Washington

Costco 401(k) Retirement Plan covers 202,468 participants in Washington, 138x the typical Washington plan (state average ~1,466 per filing). Assets: $41.0B.

$41.0B
total plan assets (2024 EOY): 202,468
covered participants: 100th
percentile by assets (of 116,472 plans): $202,587
avg assets per participant

Costco 401(k) Retirement Plan end-of-year assets rose from $33.4B in the plan year 2023 filing to $41.0B in the plan year 2024 filing.
Costco 401(k) Retirement Plan reported participants rose from 192,744 in the plan year 2023 filing to 202,468 in the plan year 2024 filing.
Costco 401(k) Retirement Plan reported net income rose from $7.5B in the plan year 2023 filing to $7.6B in the plan year 2024 filing.

See the national 2023→2024 release diff →

State

Washington

Industry

Retail Trade

Participants vs Washington filers

In Washington, the average filing covers about 1,466 participants across 2,450 plans. Costco 401(k) Retirement Plan reports 202,468 participants - 138x that state average ($41.0B EOY assets).

Washington filing particulars

Total Assets (Beginning of Year)	$33.4B
Net Assets (End of Year)	$41.0B
Net Income	$7.6B
Employer EIN	911223280
Plan Effective Date	1995-01-01
Filing Status	FILING RECEIVED

Sponsor Plan History (Costco Wholesale Corporation)

Total plan assets by year, all Costco Wholesale Corporation plans on file

Year	Plans	Participants	Total Assets
2022	2	183,100	$26.0B
2023	2	194,292	$33.5B
2024	2	203,973	$41.1B

Nearby 401(k) Plans in Washington

Peer 401(k) plans, same state, same plan type, ranked by total assets.

Costco 401(k) Retirement Plan vs. nearby 401(k) plans in Washington, assets vs. participants

The Boeing Company 401(k) Retirement Plan $73.9B · 139,394
Microsoft Corporation Savings Plus 401(k) Plan $65.6B · 118,818
Amazon 401(k) Plan $34.6B · 1,209,303
401(k) Savings Plan $10.1B · 86,668
T-Mobile USA, Inc. 401(k) Retirement Savings Plan & Trust $9.1B · 66,624

Compare Costco 401(k) Retirement Plan side-by-side with 3 peers →

Similar-Sized 401(k) Plans Nationally

401(k) plans in other states closest to Costco 401(k) Retirement Plan by total assets, not by location.

Northrop Grumman Savings Plan (VA) $39.5B · 104,719
AT&T Retirement Savings Plan (TX) $43.1B · 109,889
Fidelity Retirement Savings Plan (MA) $34.2B · 66,907
Google LLC 401(k) Savings Plan (CA) $48.7B · 116,712

Frequently Asked Questions

How did Costco 401(k) Retirement Plan assets move in 2024? ▼

Costco 401(k) Retirement Plan grew sharply - up 22.9% during 2024, from $33.4B to $41.0B. Reported net income was $7.6B.

How have Costco Wholesale Corporation plan assets changed over time? ▼

Across 3 plan years on file (2022-2024), Costco Wholesale Corporation's sponsor-wide assets grew 58.3%, from $26.0B to $41.1B.

Where does Costco 401(k) Retirement Plan rank by assets among Form 5500 filers? ▼

Costco 401(k) Retirement Plan ranks in the 100th percentile by end-of-year assets among 116,472 plans that reported assets for plan year 2024 (among the largest 1% of all filed plans).

Which 401(k) plans are similar in size to Costco 401(k) Retirement Plan? ▼

Among 401(k) plans in other states, the closest by assets is Northrop Grumman Savings Plan in VA ($39.5B, 104,719 participants).

Next read for Costco 401(k) Retirement Plan

Filing takeaways

Ways to act on Costco 401(k) Retirement Plan's numbers.

By total assets, Costco 401(k) Retirement Plan ranks among the largest 1% of all filed plans. See the largest plans
Compare it side-by-side against 3 similar 401(k) plans in Washington. Compare plans
Costco Wholesale Corporation's sponsor-wide assets have grown 58.3% since 2022 across 3 plan years on file. More Retail Trade plans

Source: U.S. Department of Labor, Employee Benefits Security Administration (EBSA), Form 5500 public disclosure dataset. Plan year 2024.

Source: DOL EFAST2 filing system (efast.dol.gov) - original filing retrieval by EIN 911223280.

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.