401(k) · DOL Form 5500 · 2023

Costco Wholesale Corporation 401(k) Plan

Data updated 2026-08-25

$33.4B
Total assets Mega-plan scale
192,744
Participants Very large workforce
100th
Percentile by assets National rank
$173,208
Avg per participant Above avg balance/head
PlainRetire home → About this data RSS: change history

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

$33.4B in assets, 192,744 participants

Costco Wholesale Corporation's Costco 401(k) Retirement Plan reported $33.4B in total assets and 192,744 participants in its 2023 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.

  • #8,413 in Retail Trade (8,414 peers)

Coverage in Washington

Costco 401(k) Retirement Plan covers 192,744 participants in Washington, 131x the typical Washington plan (state average ~1,476 per filing). Assets: $33.4B.

#8,413
in Retail Trade (8,414 peers)
+28.8%
assets growth YoY
335×
vs typical plan assets (national mean)

Costco 401(k) Retirement Plan's outsized position by total assets

Costco 401(k) Retirement Plan vs every filed plan by assets

End-of-year total assets · plan year 2023 · DOL Form 5500

$33,384,845,813 Highest reported value at or above every one of 127,068 filed plans

This plan $0 $2,050,000,000 every filed plan with reported assets, bucketed by value

Dashed line + filled bar = this entry, among filed plans.

Source U.S. Department of Labor Form 5500 filings (EBSA) · plan year 2023

Costco 401(k) Retirement Plan's mega-plan peer group by participant headcount

Plan-year 2023 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Costco 401(k) Retirement Plan is a mega filing (192,744 participants), the rightmost band on the breakdown.

What changed between DOL Form 5500 filings

plan year 2022 → plan year 2023

  • Costco 401(k) Retirement Plan reported net income rose from -$5.5B in the plan year 2022 filing to $7.5B in the plan year 2023 filing.
  • Costco 401(k) Retirement Plan end-of-year assets rose from $25.9B in the plan year 2022 filing to $33.4B in the plan year 2023 filing.
  • Costco 401(k) Retirement Plan reported participants rose from 181,505 in the plan year 2022 filing to 192,744 in the plan year 2023 filing.

See the national 2022→2023 release diff →

DOL schedule card

Filing strip 911223280 · Costco Wholesale Corporation PY 2023 · 401(k)

Costco 401(k) Retirement Plan · $33.4B · 192,744 · 100th

  • TYPE $33.4B
  • NET 192,744
  • BOOK 100th
  • VS-ST 401(k)
  • BOY near Northrop Grumman Savings Plan
  • SCH ind #8413

Stamps derive from this plan's Form 5500 line items (assets, participants, type, EIN, cohort placement) - not a quality rating of the sponsor. Read with Retail Trade retirement plans → · Plans in Washington →

Costco 401(k) Retirement Plan in the asset neighbourhood

Google LLC 401(k) Savings PlanGoogle LLC 401(k) Savings Pl…$39.0BNorthrop Grumman Savings Plan$36.2BCostco 401(k) Retirement Plan$33.4BFidelity Retirement Savings PlanFidelity Retirement Savings …$28.6BVerizon Savings Plan for Management EmployeesVerizon Savings Plan for Man…$27.8B
End-of-year total assets ($B) among Costco 401(k) Retirement Plan and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2023.

Washington filing particulars

Total Assets (Beginning of Year)$25.9B
Net Assets (End of Year)$33.4B
Net Income$7.5B
Employer EIN911223280
Plan Effective Date1995-01-01
Filing StatusFILING RECEIVED

Sponsor Plan History (Costco Wholesale Corporation)

Sponsor-wide plan assets over time

All Costco Wholesale Corporation plans reported in each filing year

Latest sponsor-wide plan assets
$41.1B 58.26330007602728% vs 2022
2024 filing year
$20B$25B$30B$35B$40B$45B 202220232024 $26B $41.1B ▲ +58.2%
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 Scatter plot of 6 data points. 050000100000150000200000 020406080 Total assets ($B) Participants Costco 401(k) Retirement Plan, Total assets ($B): 33.384845813 · Participants: 192744Costco 401(k) Retirement PlanThe Boeing Company 401(k) Retirement Plan, Total assets ($B): 72.246135158 · Participants: 128910The Boeing Company 401(k) Retirement PlanMicrosoft Corporation Savings Plus 401(k) Plan, Total assets ($B): 53.225853429 · Participants: 123296Microsoft Corporation Savings Plus 401(k) PlanT-Mobile USA, Inc. 401(k) Retirement Savings Plan & Trust, Total assets ($B): 8.338937292 · Participants: 71538T-Mobile USA, Inc. 401(k) Retirement Savings Plan & Trust401(k) Savings Plan, Total assets ($B): 8.118808679 · Participants: 87590401(k) Savings PlanProvidence Health & Services 403(b) Value Plan, Total assets ($B): 6.222775252 · Participants: 51684Providence Health & Services 403(b) Value Plan
Costco 401(k) Retirement Plan vs. nearby 401(k) plans in Washington, assets vs. participants
Compare Costco 401(k) Retirement Plan side-by-side with 3 peers →

Scale composition for Costco 401(k) Retirement Plan

Costco 401(k) Retirement Plan reports $33.4B in end-of-year assets across 192,744 participants (0.27% of the $12.3T held by all Form 5500 filers in the national rollup , and 0.21% of 93,925,755 covered participants) - about $173,208 per participant (1.3x the national average assets-per-participant) . Net income for plan year 2023 was $7.5B.

This plan identity (EIN 911223280, plan #002) has 3 Form 5500 filings on file from 2022 to 2024 , with end-of-year assets moving from $25.9B to $41.0B (+58.3%) while covered participants moved from 181,505 to 202,468 . Single-year sparse filers cannot show that trail.

Plan year Participants EOY assets Filing
2022 181,505 $25.9B Open filing
2023 192,744 $33.4B This page
2024 · index core 202,468 $41.0B Open filing

The same sponsor also keeps 2 other index-core plans on PlainRetire:

Costco 401(k) Retirement Plan's out-of-state 401(k) peers by assets and headcount

Outside Washington, the nearest 401(k) by assets is Northrop Grumman Savings Plan in VA ($36.2B); by covered participants it is Wells Fargo & Company 401(k) Plan in CA (193,919 participants). Same-state nearby plans are listed separately above.

Closest by plan assets

Nearest other-state filings by tot_assets_eoy ($33.4B here).

Similar participant headcount

Nearest other-state filings by covered participants (192,744 participants); asset peers above are excluded.

DOL Form 5500 plan year 2023. Asset totals can differ widely at the same headcount; neither axis is a quality rating.

Frequently Asked Questions

How did Costco 401(k) Retirement Plan assets move in 2023? ▼
Costco 401(k) Retirement Plan grew sharply - up 28.8% during 2023, from $25.9B to $33.4B. Reported net income was $7.5B.
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 127,072 plans that reported assets for plan year 2023 (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 ($36.2B, 97,987 participants).
Which 401(k) plans cover a similar participant headcount to Costco 401(k) Retirement Plan? ▼
Among 401(k) plans in other states, the closest by covered participants is Wells Fargo & Company 401(k) Plan in CA (193,919 participants, $51.8B in assets).

Source: U.S. Department of Labor, Employee Benefits Security Administration (EBSA), Form 5500 public disclosure dataset. Plan year 2023.

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.