401(k) · DOL Form 5500 · 2024

The Middlesex Corporation 401(k) Plan

Data updated 2026-08-25

$118M
Total assets Near avg plan size
821
Participants Near avg headcount
92nd
Percentile by assets National rank
$143,603
Avg per participant Near avg balance/head
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Official DOL plan name: Middlesex Corporation Retirement Savings Plan · Sponsored by The Middlesex Corporation · Massachusetts · Construction

$118M in assets, 821 participants

The Middlesex Corporation's Middlesex Corporation Retirement Savings Plan reported $118M in total assets and 821 participants in its 2024 DOL Form 5500 filing, ranking in the 92nd 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.

  • #8,138 in Construction (9,039 peers)

Where Middlesex Corporation Retirement Savings Plan sits by assets

Middlesex Corporation Retirement Savings Plan sits in the top 10% of all filed plans by assets, $118M for 821 participants (~$143,603/participant), up 14.8% in 2024.

#8,138
in Construction (9,039 peers)
+14.8%
assets growth YoY
1.2×
vs typical plan assets (national mean)

Middlesex Corporation Retirement Savings Plan's outsized position by total assets

Middlesex Corporation Retirement Savings Plan vs every filed plan by assets

End-of-year total assets · plan year 2024 · DOL Form 5500

$117,897,915 Top 8% higher than 92% of 123,620 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 2024

Middlesex Corporation Retirement Savings Plan among mid-size filed plans by headcount

Plan-year 2024 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Middlesex Corporation Retirement Savings Plan sits mid-pack in the medium band (821 participants).

What changed between DOL Form 5500 filings

plan year 2023 → plan year 2024

  • Middlesex Corporation Retirement Savings Plan end-of-year assets rose from $103M in the plan year 2023 filing to $118M in the plan year 2024 filing.
  • Middlesex Corporation Retirement Savings Plan reported participants rose from 772 in the plan year 2023 filing to 821 in the plan year 2024 filing.
  • Middlesex Corporation Retirement Savings Plan reported net income fell from $16M in the plan year 2023 filing to $15M in the plan year 2024 filing.

See the national 2023→2024 release diff →

Plan-year Form 5500 strip

Filing strip 042534615 · The Middlesex Corporation PY 2024 · 401(k)

Middlesex Corporation Retirement Savings Plan · $118M · 821 · 92nd

  • IND $118M
  • EOY 821
  • 5500 92nd
  • ASSETS 401(k)
  • PCT near Construction Specialties, Inc. Ret Savings Plan
  • EIN ind #8138

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 Construction retirement plans → · Plans in Massachusetts →

Middlesex Corporation Retirement Savings Plan in the asset neighbourhood

The Anchin, Block & Anchin Savings PlanThe Anchin, Block & Anchin S…$118MInari Medical, Inc. 401(k) PlanInari Medical, Inc. 401(k) P…$118MLas Vegas Sands Corp. 401(k) Retirement PlanLas Vegas Sands Corp. 401(k)…$118MMiddlesex Corporation Retirement Savings PlanMiddlesex Corporation Retire…$118MConstruction Specialties, Inc. Ret Savings PlanConstruction Specialties, In…$118M
End-of-year total assets ($M) among Middlesex Corporation Retirement Savings Plan and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2024.

Scale-class filing particulars (2024)

Total Assets (Beginning of Year)$103M
Net Assets (End of Year)$118M
Net Income$15M
Employer EIN042534615
Plan Effective Date1992-10-16
Filing StatusFILING RECEIVED

Sponsor Plan History (The Middlesex Corporation)

Sponsor-wide plan assets over time

All The Middlesex Corporation plans reported in each filing year

Latest sponsor-wide plan assets
$118M 35.60155500814038% vs 2022
2024 filing year
$80M$90M$100M$110M$120M$130M 202220232024 $86.9M $118M ▲ +35.6%
Year Plans Participants Total Assets
2022 1 868 $87M
2023 1 772 $103M
2024 1 821 $118M

Nearby 401(k) Plans in Massachusetts

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

Middlesex Corporation Retirement Savings Plan vs. nearby 401(k) plans in Massachusetts, assets vs. participants Scatter plot of 6 data points. -20000020000400006000080000 -10010203040 Total assets ($B) Participants Middlesex Corporation Retirement Savings Plan, Total assets ($B): 0.117897915 · Participants: 821Middlesex Corporation Retirement Savings PlanFidelity Retirement Savings Plan, Total assets ($B): 34.201609937 · Participants: 66907Fidelity Retirement Savings PlanLiberty Mutual 401(k) Plan, Total assets ($B): 11.352606499 · Participants: 34618Liberty Mutual 401(k) PlanMassachusetts Institute of Technology Supplemental 401(k) Plan, Total assets ($B): 7.720373045 · Participants: 14762Massachusetts Institute of Technology Supplemental 401(k) PlanBoston Scientific Corporation 401(k) Retirement Savings Plan, Total assets ($B): 6.775289067 · Participants: 20639Boston Scientific Corporation 401(k) Retirement Savings PlanState Street Salary Savings Program, Total assets ($B): 6.532301643 · Participants: 12777State Street Salary Savings Program
Middlesex Corporation Retirement Savings Plan vs. nearby 401(k) plans in Massachusetts, assets vs. participants
Compare Middlesex Corporation Retirement Savings Plan side-by-side with 3 peers →

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

Outside Massachusetts, the nearest 401(k) by assets is Construction Specialties, Inc. Ret Savings Plan in NJ ($118M); by covered participants it is 401(k) Profit Sharing Plan for Employees of Great Western Dining Service, Inc. in MO (821 participants). Same-state nearby plans are listed separately above.

Closest by plan assets

Nearest other-state filings by tot_assets_eoy ($118M here).

Similar participant headcount

Nearest other-state filings by covered participants (821 participants); asset peers above are excluded.

DOL Form 5500 plan year 2024. Asset totals can differ widely at the same headcount; neither axis is a quality rating.

Frequently Asked Questions

How did Middlesex Corporation Retirement Savings Plan assets move in 2024? ▼
Middlesex Corporation Retirement Savings Plan grew at a solid clip - up 14.8% during 2024, from $103M to $118M. Reported net income was $15M.
How have The Middlesex Corporation plan assets changed over time? ▼
Across 3 plan years on file (2022-2024), The Middlesex Corporation's sponsor-wide assets grew 35.6%, from $87M to $118M.
Where does Middlesex Corporation Retirement Savings Plan rank by assets among Form 5500 filers? ▼
Middlesex Corporation Retirement Savings Plan ranks in the 92nd percentile by end-of-year assets among 123,622 plans that reported assets for plan year 2024 (in the top 10% of all filed plans by assets).
Which 401(k) plans are similar in size to Middlesex Corporation Retirement Savings Plan? ▼
Among 401(k) plans in other states, the closest by assets is Construction Specialties, Inc. Ret Savings Plan in NJ ($118M, 765 participants).
Which 401(k) plans cover a similar participant headcount to Middlesex Corporation Retirement Savings Plan? ▼
Among 401(k) plans in other states, the closest by covered participants is 401(k) Profit Sharing Plan for Employees of Great Western Dining Service, Inc. in MO (821 participants, N/A in assets).

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 042534615.

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.