401(k) · DOL Form 5500 · 2024

William Blair & Company, LLC 401(k) Plan

Data updated 2026-07-24

$1.2B
Total assets: 1,816
Participants: 99th
Percentile by assets: $657,497
Avg per participant

Official DOL plan name: William Blair 401(k) and Profit Sharing Plan · Sponsored by William Blair & Company, LLC · Illinois · Finance & Insurance

$1.2B in assets, 1,816 participants

William Blair & Company, LLC's William Blair 401(k) and Profit Sharing Plan reported $1.2B in total assets and 1,816 participants in its 2024 DOL Form 5500 filing, ranking in the 99th 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.

99th percentile by assets (of 116,472 plans)

Coverage in Illinois

William Blair 401(k) and Profit Sharing Plan covers 1,816 participants in Illinois, 2.4x the typical Illinois plan (state average ~768 per filing). Assets: $1.2B.

$1.2B
total plan assets (2024 EOY): 1,816
covered participants: 99th
percentile by assets (of 116,472 plans): $657,497
avg assets per participant

William Blair 401(k) and Profit Sharing Plan reported net income fell from $174M in the plan year 2023 filing to $134M in the plan year 2024 filing.
William Blair 401(k) and Profit Sharing Plan end-of-year assets rose from $1.1B in the plan year 2023 filing to $1.2B in the plan year 2024 filing.
William Blair 401(k) and Profit Sharing Plan reported participants fell from 1,979 in the plan year 2023 filing to 1,816 in the plan year 2024 filing.

See the national 2023→2024 release diff →

State

Illinois

Industry

Finance & Insurance

Participants vs Illinois filers

In Illinois, the average filing covers about 768 participants across 5,440 plans. William Blair 401(k) and Profit Sharing Plan reports 1,816 participants - 2.4x that state average ($1.2B EOY assets).

Illinois filing particulars

Total Assets (Beginning of Year)	$1.1B
Net Assets (End of Year)	$1.2B
Net Income	$134M
Employer EIN	362214610
Plan Effective Date	1953-12-14
Filing Status	FILING RECEIVED

Sponsor Plan History (William Blair & Company, LLC)

Total plan assets by year, all William Blair & Company, LLC plans on file

Year	Plans	Participants	Total Assets
2022	1	1,812	$886M
2023	1	1,979	$1.1B
2024	1	1,816	$1.2B

Nearby 401(k) Plans in Illinois

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

William Blair 401(k) and Profit Sharing Plan vs. nearby 401(k) plans in Illinois, assets vs. participants

Accenture United States 401(k) Match and Savings Plan $21.3B · 66,965
State Farm 401(k) Savings Plan $19.0B · 63,297
United Airlines Pilot Retirement Account Plan $16.8B · 16,659
Abbott Laboratories Stock Retirement Plan $15.8B · 38,229
Walgreens Retirement Savings Plan $14.5B · 233,635

Compare William Blair 401(k) and Profit Sharing … side-by-side with 3 peers →

Similar-Sized 401(k) Plans Nationally

401(k) plans in other states closest to William Blair 401(k) and Profit Sharing Plan by total assets, not by location.

The Lonza US Savings Plan (NJ) $1.2B · 4,689
Expeditors International of Washington, Inc. 401(k) Plan (WA) $1.2B · 6,343
Nomura Securities International, Inc. Retirement Investment Plan (NY) $1.2B · 2,107
Sunbelt Rentals, Inc. Retirement Savings Plan (SC) $1.2B · 20,374

Frequently Asked Questions

How did William Blair 401(k) and Profit Sharing Plan assets move in 2024? ▼

William Blair 401(k) and Profit Sharing Plan grew at a solid clip - up 12.7% during 2024, from $1.1B to $1.2B. Reported net income was $134M.

How have William Blair & Company, LLC plan assets changed over time? ▼

Across 3 plan years on file (2022-2024), William Blair & Company, LLC's sponsor-wide assets grew 34.8%, from $886M to $1.2B.

Where does William Blair 401(k) and Profit Sharing Plan rank by assets among Form 5500 filers? ▼

William Blair 401(k) and Profit Sharing Plan ranks in the 99th 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 William Blair 401(k) and Profit Sharing Plan? ▼

Among 401(k) plans in other states, the closest by assets is The Lonza US Savings Plan in NJ ($1.2B, 4,689 participants).

Next read for William Blair 401(k) and Profit Sharing …

Filing takeaways

Ways to act on William Blair 401(k) and Profit Sharing Plan's numbers.

By total assets, William Blair 401(k) and Profit Sharing 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 Illinois. Compare plans
William Blair & Company, LLC's sponsor-wide assets have grown 34.8% since 2022 across 3 plan years on file. More Finance & Insurance 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 362214610.

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.