401(k) · DOL Form 5500 · 2023

Immunogen, Inc. 401(k) Plan

Data updated 2026-08-25

$73M
Total assets Below avg plan size
276
Participants Below avg headcount
89th
Percentile by assets National rank
$265,703
Avg per participant High balance/head
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Official DOL plan name: Immunogen, Inc. 401(k) Plan and Trust · Sponsored by Immunogen, Inc. · Massachusetts · Professional & Technical Services

$73M in assets, 276 participants

Immunogen, Inc.'s Immunogen, Inc. 401(k) Plan and Trust reported $73M in total assets and 276 participants in its 2023 DOL Form 5500 filing, ranking in the 89th 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.

  • #18,337 in Professional & Technical Services (20,321 peers)

Coverage in Massachusetts

Immunogen, Inc. 401(k) Plan and Trust covers 276 participants in Massachusetts, about 42% of the average Massachusetts filer (state average ~659 per filing). Assets: $73M.

#18,337
in Professional & Technical Services (20,321 peers)
+25.4%
assets growth YoY
0.7×
vs typical plan assets (national mean)

Immunogen, Inc. 401(k) Plan and Trust's outsized position by total assets

Immunogen, Inc. 401(k) Plan and Trust vs every filed plan by assets

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

$73,333,902 Top 11% higher than 89% 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

Immunogen, Inc. 401(k) Plan and Trust among mid-size filed plans by headcount

Plan-year 2023 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Immunogen, Inc. 401(k) Plan and Trust sits mid-pack in the medium band (276 participants).

What changed between DOL Form 5500 filings

plan year 2022 → plan year 2023

  • Immunogen, Inc. 401(k) Plan and Trust reported net income rose from -$9M in the plan year 2022 filing to $15M in the plan year 2023 filing.
  • Immunogen, Inc. 401(k) Plan and Trust reported participants rose from 106 in the plan year 2022 filing to 276 in the plan year 2023 filing.
  • Immunogen, Inc. 401(k) Plan and Trust end-of-year assets rose from $58M in the plan year 2022 filing to $73M in the plan year 2023 filing.

See the national 2022→2023 release diff →

Plan-year Form 5500 strip

Filing strip 042726691 · Immunogen, Inc. PY 2023 · 401(k)

Immunogen, Inc. 401(k) Plan and Trust · $73M · 276 · 89th

  • IND $73M
  • EOY 276
  • 5500 89th
  • ASSETS 401(k)
  • PCT near Cbc/Cts 401(k) Plan
  • EIN ind #18337

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 Professional & Technical Services retirement plans → · Plans in Massachusetts →

Immunogen, Inc. 401(k) Plan and Trust in the asset neighbourhood

Cbc/Cts 401(k) Plan$73MIcr, Inc. Retirement Trust$73MImmunogen, Inc. 401(k) Plan and TrustImmunogen, Inc. 401(k) Plan …$73MCcb 401(k) Retirement Plan$73MPerfetti Van Melle, Inc. 401(k) Plan and TrustPerfetti Van Melle, Inc. 401…$73M
End-of-year total assets ($M) among Immunogen, Inc. 401(k) Plan and Trust and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2023.

Massachusetts filing particulars

Total Assets (Beginning of Year)$58M
Net Assets (End of Year)$73M
Net Income$15M
Employer EIN042726691
Plan Effective Date1990-09-01
Filing StatusFILING RECEIVED

Sponsor Plan History (Immunogen, Inc.)

Sponsor-wide plan assets over time

All Immunogen, Inc. plans reported in each filing year

Latest sponsor-wide plan assets
$82M 39.855092645331226% vs 2022
2024 filing year
$50M$60M$70M$80M$90M 202220232024 $58.5M $81.8M ▲ +39.9%
Year Plans Participants Total Assets
2022 1 106 $58M
2023 1 276 $73M
2024 1 295 $82M

Nearby 401(k) Plans in Massachusetts

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

Immunogen, Inc. 401(k) Plan and Trust vs. nearby 401(k) plans in Massachusetts, assets vs. participants Scatter plot of 6 data points. -20000020000400006000080000 -10010203040 Total assets ($B) Participants Immunogen, Inc. 401(k) Plan and Trust, Total assets ($B): 0.073333902 · Participants: 276Immunogen, Inc. 401(k) Plan and TrustFidelity Retirement Savings Plan, Total assets ($B): 28.649852331 · Participants: 62289Fidelity Retirement Savings PlanLiberty Mutual 401(k) Plan, Total assets ($B): 10.556596852 · Participants: 37052Liberty Mutual 401(k) PlanMassachusetts Institute of Technology Supplemental 401(k) Plan, Total assets ($B): 6.829912863 · Participants: 14094Massachusetts Institute of Technology Supplemental 401(k) PlanBoston Scientific Corporation 401(k) Retirement Savings Plan, Total assets ($B): 5.786107181 · Participants: 19881Boston Scientific Corporation 401(k) Retirement Savings PlanPhilips North America 401(k) Plan, Total assets ($B): 5.779286156 · Participants: 19120Philips North America 401(k) Plan
Immunogen, Inc. 401(k) Plan and Trust vs. nearby 401(k) plans in Massachusetts, assets vs. participants
Compare Immunogen, Inc. 401(k) Plan and Trust side-by-side with 3 peers →

Immunogen, Inc. 401(k) Plan and Trust's out-of-state 401(k) peers by assets and headcount

Outside Massachusetts, the nearest 401(k) by assets is Cbc/Cts 401(k) Plan in OH ($73M); by covered participants it is Sojern, Inc. 401(k) Plan in NE (276 participants). Same-state nearby plans are listed separately above.

Closest by plan assets

Nearest other-state filings by tot_assets_eoy ($73M here).

Similar participant headcount

Nearest other-state filings by covered participants (276 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 Immunogen, Inc. 401(k) Plan and Trust assets move in 2023? ▼
Immunogen, Inc. 401(k) Plan and Trust grew sharply - up 25.4% during 2023, from $58M to $73M. Reported net income was $15M.
How have Immunogen, Inc. plan assets changed over time? ▼
Across 3 plan years on file (2022-2024), Immunogen, Inc.'s sponsor-wide assets grew 39.9%, from $58M to $82M.
Where does Immunogen, Inc. 401(k) Plan and Trust rank by assets among Form 5500 filers? ▼
Immunogen, Inc. 401(k) Plan and Trust ranks in the 89th percentile by end-of-year assets among 127,072 plans that reported assets for plan year 2023 (in the top quartile of all filed plans by assets).
Which 401(k) plans are similar in size to Immunogen, Inc. 401(k) Plan and Trust? ▼
Among 401(k) plans in other states, the closest by assets is Cbc/Cts 401(k) Plan in OH ($73M, 1,160 participants).
Which 401(k) plans cover a similar participant headcount to Immunogen, Inc. 401(k) Plan and Trust? ▼
Among 401(k) plans in other states, the closest by covered participants is Sojern, Inc. 401(k) Plan in NE (276 participants, $23M 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 042726691.

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.