401(k) · DOL Form 5500 · 2023

Biogen Inc. 401(k) Plan

Data updated 2026-08-11

$1.9B
Total assets
5,003
Participants
99th
Percentile by assets
$387,385
Avg per participant
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Official DOL plan name: Biogen 401(k) Savings Plan · Sponsored by Biogen Inc. · Massachusetts · Manufacturing

$1.9B in assets, 5,003 participants

Biogen Inc.'s Biogen 401(k) Savings Plan reported $1.9B in total assets and 5,003 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.

  • 99th percentile by assets (of 127,072 plans)
  • #18,470 in Manufacturing (18,722 peers)

Coverage in Massachusetts

Biogen 401(k) Savings Plan covers 5,003 participants in Massachusetts, 7.6x the typical Massachusetts plan (state average ~659 per filing). Assets: $1.9B.

$1.9B
total plan assets (2023 EOY)
5,003
covered participants
99th
percentile by assets (of 127,072 plans)
$387,385
avg assets per participant

What changed between DOL Form 5500 filings

plan year 2022 → plan year 2023

  • Biogen 401(k) Savings Plan reported net income rose from -$408M in the plan year 2022 filing to $303M in the plan year 2023 filing.
  • Biogen 401(k) Savings Plan end-of-year assets rose from $1.6B in the plan year 2022 filing to $1.9B in the plan year 2023 filing.
  • Biogen 401(k) Savings Plan reported participants fell from 5,611 in the plan year 2022 filing to 5,003 in the plan year 2023 filing.

See the national 2022→2023 release diff →

Industry

Participants vs Massachusetts filers

In Massachusetts, the average filing covers about 659 participants across 4,265 plans. Biogen 401(k) Savings Plan reports 5,003 participants - 7.6x that state average ($1.9B EOY assets).

Massachusetts filing particulars

Total Assets (Beginning of Year)$1.6B
Net Assets (End of Year)$1.9B
Net Income$303M
Employer EIN330112644
Plan Effective Date2004-01-06
Filing StatusFILING RECEIVED

Sponsor Plan History (Biogen Inc.)

$1.4B$1.6B$1.8B$2B$2.2B$2.4B 202220232024 $1.6B $2.16B ▲ +35.0%
Total plan assets by year, all Biogen Inc. plans on file
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

Biogen 401(k) Savings Plan vs. nearby 401(k) plans in Massachusetts, assets vs. participants Scatter plot of 6 data points. 020000400006000080000 0102030 Total assets ($B) Participants Biogen 401(k) Saving…Fidelity Retirement …Liberty Mutual 401(k…Massachusetts Instit…Boston Scientific Co…Philips North Americ…
Biogen 401(k) Savings Plan vs. nearby 401(k) plans in Massachusetts, assets vs. participants

Scale composition for Biogen 401(k) Savings Plan

Biogen 401(k) Savings Plan reports $1.9B in end-of-year assets across 5,003 participants (0.016% of the $12.3T held by all Form 5500 filers in the national rollup , and 0.005% of 93,925,755 covered participants) - about $387,385 per participant (2.8x the national average assets-per-participant) . Net income for plan year 2023 was $303M.

This plan identity (EIN 330112644, plan #001) has 3 Form 5500 filings on file from 2022 to 2024 , with end-of-year assets moving from $1.6B to $2.2B (+34.8%) while covered participants moved from 5,611 to 4,292 . Single-year sparse filers cannot show that trail.

Plan year Participants EOY assets Filing
2022 5,611 $1.6B Open filing
2023 5,003 $1.9B This page
2024 · index core 4,292 $2.2B Open filing

The same sponsor also keeps 1 other index-core plan on PlainRetire:

Similar-Sized 401(k) Plans Nationally

401(k) plans in other states closest to Biogen 401(k) Savings Plan by total assets, not by location.

Frequently Asked Questions

How did Biogen 401(k) Savings Plan assets move in 2023?
Biogen 401(k) Savings Plan grew sharply - up 21.0% during 2023, from $1.6B to $1.9B. Reported net income was $303M.
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 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 Biogen 401(k) Savings Plan?
Among 401(k) plans in other states, the closest by assets is Park Nicollet Health Services 401(k) Retirement Savings Plan in MN ($1.9B, 7,819 participants).

Filing takeaways

Ways to act on Biogen 401(k) Savings Plan's numbers.