401(k) · DOL Form 5500 · 2024

Biogen Inc. 401(k) Plan

Data updated 2026-08-25

$2.2B
Total assets Very large vs avg
4,292
Participants Above avg headcount
99th
Percentile by assets National rank
$503,073
Avg per participant High balance/head
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Official DOL plan name: Biogen 401(k) Savings Plan · Sponsored by Biogen Inc. · Massachusetts · Manufacturing

$2.2B in assets, 4,292 participants

Biogen Inc.'s Biogen 401(k) Savings Plan reported $2.2B in total assets and 4,292 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.

  • #17,547 in Manufacturing (17,777 peers)

Coverage in Massachusetts

Biogen 401(k) Savings Plan covers 4,292 participants in Massachusetts, 6.5x the typical Massachusetts plan (state average ~659 per filing). Assets: $2.2B.

#17,547
in Manufacturing (17,777 peers)
+11.4%
assets growth YoY
22×
vs typical plan assets (national mean)

Biogen 401(k) Savings Plan's outsized position by total assets

Biogen 401(k) Savings Plan vs every filed plan by assets

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

$2,159,190,583 Top 1% higher than 99% 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

Biogen 401(k) Savings Plan's large-plan peer group by participant headcount

Plan-year 2024 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Biogen 401(k) Savings Plan lands in the large band (4,292 participants).

What changed between DOL Form 5500 filings

plan year 2023 → plan year 2024

  • Biogen 401(k) Savings Plan reported net income fell from $303M in the plan year 2023 filing to $221M in the plan year 2024 filing.
  • Biogen 401(k) Savings Plan reported participants fell from 5,003 in the plan year 2023 filing to 4,292 in the plan year 2024 filing.
  • Biogen 401(k) Savings Plan end-of-year assets rose from $1.9B in the plan year 2023 filing to $2.2B in the plan year 2024 filing.

See the national 2023→2024 release diff →

DOL schedule card

Filing strip 330112644 · Biogen Inc. PY 2024 · 401(k)

Biogen 401(k) Savings Plan · $2.2B · 4,292 · 99th

  • ASSETS $2.2B
  • PCT 4,292
  • EIN 99th
  • RANK 401(k)
  • PHOTO near Tetra Tech, Inc. and Subsidiaries Retirement Plan
  • IND ind #17547

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 Manufacturing retirement plans → · Plans in Massachusetts →

Biogen 401(k) Savings Plan in the asset neighbourhood

Biogen 401(k) Savings Plan$2.2BTetra Tech, Inc. and Subsidiaries Retirement PlanTetra Tech, Inc. and Subsidi…$2.2BMedamerica 401(k) Profit Sharing Plan for Employees of VituityMedamerica 401(k) Profit Sha…$2.2BAllianz Asset Management of America 401(k) Savings and Retirement PlanAllianz Asset Management of …$2.2BAssurant 401(k) Plan$2.2B
End-of-year total assets ($B) among Biogen 401(k) Savings Plan and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2024.

Massachusetts filing particulars

Total Assets (Beginning of Year)$1.9B
Net Assets (End of Year)$2.2B
Net Income$221M
Employer EIN330112644
Plan Effective Date2004-01-06
Filing StatusFILING RECEIVED

Sponsor Plan History (Biogen Inc.)

Sponsor-wide plan assets over time

All Biogen Inc. plans reported in each filing year

Latest sponsor-wide plan assets
$2.2B 34.84383057226459% vs 2022
2024 filing year
$1.4B$1.6B$1.8B$2B$2.2B$2.4B 202220232024 $1.6B $2.16B ▲ +35.0%
Year Plans Participants Total Assets
2022 1 5,611 $1.6B
2023 1 5,003 $1.9B
2024 1 4,292 $2.2B

Nearby 401(k) Plans in Massachusetts

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

Biogen 401(k) Savings Plan vs. nearby 401(k) plans in Massachusetts, assets vs. participants Scatter plot of 6 data points. 020000400006000080000 010203040 Total assets ($B) Participants Biogen 401(k) Savings Plan, Total assets ($B): 2.159190583 · Participants: 4292Biogen 401(k) 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
Biogen 401(k) Savings Plan vs. nearby 401(k) plans in Massachusetts, assets vs. participants
Compare Biogen 401(k) Savings Plan side-by-side with 3 peers →

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

Outside Massachusetts, the nearest 401(k) by assets is Tetra Tech, Inc. and Subsidiaries Retirement Plan in CT ($2.2B); by covered participants it is Blue Cross and Blue Shield of Al 401(k) Plan Salary Deferral Plan in AL (4,291 participants). Same-state nearby plans are listed separately above.

Similar participant headcount

Nearest other-state filings by covered participants (4,292 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 Biogen 401(k) Savings Plan assets move in 2024? ▼
Biogen 401(k) Savings Plan grew at a solid clip - up 11.4% during 2024, from $1.9B to $2.2B. Reported net income was $221M.
How have Biogen Inc. plan assets changed over time? ▼
Across 3 plan years on file (2022-2024), Biogen Inc.'s sponsor-wide assets grew 34.8%, from $1.6B to $2.2B.
Where does Biogen 401(k) Savings Plan rank by assets among Form 5500 filers? ▼
Biogen 401(k) Savings Plan ranks in the 99th percentile by end-of-year assets among 123,622 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 Biogen 401(k) Savings Plan? ▼
Among 401(k) plans in other states, the closest by assets is Tetra Tech, Inc. and Subsidiaries Retirement Plan in CT ($2.2B, 11,882 participants).
Which 401(k) plans cover a similar participant headcount to Biogen 401(k) Savings Plan? ▼
Among 401(k) plans in other states, the closest by covered participants is Blue Cross and Blue Shield of Al 401(k) Plan Salary Deferral Plan in AL (4,291 participants, $880M 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 330112644.

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.