401(k) · DOL Form 5500 · 2023

William Blair & Company, LLC 401(k) Plan

Data updated 2026-08-25

$1.1B
Total assets Very large vs avg
1,979
Participants Near avg headcount
99th
Percentile by assets National rank
$535,456
Avg per participant High balance/head
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Official DOL plan name: William Blair 401(k) and Profit Sharing Plan · Sponsored by William Blair & Company, LLC · Illinois · Finance & Insurance

$1.1B in assets, 1,979 participants

William Blair & Company, LLC's William Blair 401(k) and Profit Sharing Plan reported $1.1B in total assets and 1,979 participants in its 2023 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.

  • #8,655 in Finance & Insurance (8,869 peers)

Coverage in Illinois

William Blair 401(k) and Profit Sharing Plan covers 1,979 participants in Illinois, 2.5x the typical Illinois plan (state average ~779 per filing). Assets: $1.1B.

#8,655
in Finance & Insurance (8,869 peers)
+19.6%
assets growth YoY
11×
vs typical plan assets (national mean)

William Blair 401(k) and Profit Sharing Plan's outsized position by total assets

William Blair 401(k) and Profit Sharing Plan vs every filed plan by assets

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

$1,059,667,291 Top 1% higher than 99% 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

William Blair 401(k) and Profit Sharing Plan's large-plan peer group by participant headcount

Plan-year 2023 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. William Blair 401(k) and Profit Sharing Plan lands in the large band (1,979 participants).

What changed between DOL Form 5500 filings

plan year 2022 → plan year 2023

  • William Blair 401(k) and Profit Sharing Plan reported net income rose from -$167M in the plan year 2022 filing to $174M in the plan year 2023 filing.
  • William Blair 401(k) and Profit Sharing Plan end-of-year assets rose from $886M in the plan year 2022 filing to $1.1B in the plan year 2023 filing.
  • William Blair 401(k) and Profit Sharing Plan reported participants rose from 1,812 in the plan year 2022 filing to 1,979 in the plan year 2023 filing.

See the national 2022→2023 release diff →

Plan-year Form 5500 strip

Filing strip 362214610 · William Blair & Company, LLC PY 2023 · 401(k)

William Blair 401(k) and Profit Sharing Plan · $1.1B · 1,979 · 99th

  • EOY $1.1B
  • EOY 1,979
  • EOY 99th
  • EOY 401(k)
  • EOY near Teco Energy Group Retirement Savings Plan
  • EOY ind #8655

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 Finance & Insurance retirement plans → · Plans in Illinois →

William Blair 401(k) and Profit Sharing Plan in the asset neighbourhood

William Blair 401(k) and Profit Sharing PlanWilliam Blair 401(k) and Pro…$1.1BTeco Energy Group Retirement Savings PlanTeco Energy Group Retirement…$1.1BKing & Spalding LLP Profit Sharing - 401(k) PlanKing & Spalding LLP Profit S…$1.1BG & a Partners Multiple Employer 401(k) PlanG & a Partners Multiple Empl…$1.1BOrrick, Herrington & Sutcliffe LLP Retirement PlanOrrick, Herrington & Sutclif…$1.1B
End-of-year total assets ($B) among William Blair 401(k) and Profit Sharing Plan and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2023.

Illinois filing particulars

Total Assets (Beginning of Year)$886M
Net Assets (End of Year)$1.1B
Net Income$174M
Employer EIN362214610
Plan Effective Date1953-12-14
Filing StatusFILING RECEIVED

Sponsor Plan History (William Blair & Company, LLC)

Sponsor-wide plan assets over time

All William Blair & Company, LLC plans reported in each filing year

Latest sponsor-wide plan assets
$1.2B 34.77360637489787% vs 2022
2024 filing year
$0.8B$0.9B$1B$1.1B$1.2B$1.3B 202220232024 $0.89B $1.19B ▲ +33.7%
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 Scatter plot of 6 data points. -1000000100000200000300000 05101520 Total assets ($B) Participants William Blair 401(k) and Profit Sharing Plan, Total assets ($B): 1.059667291 · Participants: 1979William Blair 401(k) and Profit Sharing PlanAccenture United States 401(k) Match Savings Plan, Total assets ($B): 17.594548115 · Participants: 69974Accenture United States 401(k) Match Savings PlanState Farm 401(k) Savings Plan, Total assets ($B): 16.935002041 · Participants: 60246State Farm 401(k) Savings PlanAbbott Laboratories Stock Retirement Plan, Total assets ($B): 14.496191 · Participants: 38012Abbott Laboratories Stock Retirement PlanUnited Airlines Pilot Retirement Account Plan, Total assets ($B): 14.367975914 · Participants: 14959United Airlines Pilot Retirement Account PlanWalgreens Retirement Savings Plan, Total assets ($B): 13.444551767 · Participants: 235331Walgreens Retirement Savings Plan
William Blair 401(k) and Profit Sharing Plan vs. nearby 401(k) plans in Illinois, assets vs. participants
Compare William Blair 401(k) and Profit Sharing Plan side-by-side with 3 peers →

William Blair 401(k) and Profit Sharing Plan's out-of-state 401(k) peers by assets and headcount

Outside Illinois, the nearest 401(k) by assets is Teco Energy Group Retirement Savings Plan in FL ($1.1B); by covered participants it is Alku 401(k) Plan in MA (1,979 participants). Same-state nearby plans are listed separately above.

Closest by plan assets

Nearest other-state filings by tot_assets_eoy ($1.1B here).

Similar participant headcount

Nearest other-state filings by covered participants (1,979 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 William Blair 401(k) and Profit Sharing Plan assets move in 2023? ▼
William Blair 401(k) and Profit Sharing Plan grew sharply - up 19.6% during 2023, from $886M to $1.1B. Reported net income was $174M.
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 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 William Blair 401(k) and Profit Sharing Plan? ▼
Among 401(k) plans in other states, the closest by assets is Teco Energy Group Retirement Savings Plan in FL ($1.1B, 3,917 participants).
Which 401(k) plans cover a similar participant headcount to William Blair 401(k) and Profit Sharing Plan? ▼
Among 401(k) plans in other states, the closest by covered participants is Alku 401(k) Plan in MA (1,979 participants, $52M 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 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.