Biogen Inc. 401(k) Plan: Login, Facts & Contact Information
Biogen Inc. 401(k) Login
3,495 former Biogen Inc. employees still have money in this plan.
Retirement plan providers can change. This information is from the plan's 2024 filing.
Biogen Inc. 401(k) Plan Facts
Source: Form 5500 for plan year 2024 (Jan 1, 2024 – Dec 31, 2024), filed Oct 14, 2025. Public filing with the U.S. Department of Labor.
Money in and out in plan year 2024
- $133.4 million went into the plan in contributions, $46.2 million of it from the employer (35%).
- $251.9 million was paid out to participants.
- Investment and other income added $339.5 million.
How the Biogen Inc. 401(k) changed, 2019–2024
| Plan year | Participants | Plan assets | Employer contributions | Benefits paid |
|---|---|---|---|---|
| 2019 | 6,878 | $1.35 billion | $41.8 million | $92.7 million |
| 2020 | 7,255 | $1.70 billion | $48.8 million | $109.8 million |
| 2021 | 8,247 | $2.01 billion | $54.8 million | $136.4 million |
| 2022 | 8,420 | $1.60 billion | $52.9 million | $169.4 million |
| 2023 | 8,349 | $1.94 billion | $51.7 million | $188.1 million |
| 2024 | 8,088 | $2.16 billion | $46.2 million | $251.9 million |
Biogen Inc. 401(k) Contact Information
Questions about the Biogen Inc. 401(k)
Does Biogen Inc contribute to the 401(k)?
Yes. The plan reports an employer contribution arrangement. In plan year 2024 the employer contributed $46.2 million, 35% of all contributions.
Does the Biogen Inc 401(k) have automatic enrollment?
No. The plan does not report automatic enrollment; employees enroll themselves.
How many people are in the Biogen Inc 401(k) plan?
8,088 participants at the start of plan year 2024, 4,289 of them active employees, and 3,495 former employees who still had money in the plan.
What is the average 401(k) balance at Biogen Inc?
About $282,765 per account: $2.16 billion in plan assets across 7,636 accounts with a balance at the end of plan year 2024.
Who manages the Biogen Inc 401(k) accounts?
Fidelity NetBenefits (listed on the filing as FIDELITY INVESTMENTS INSTITUTIONAL) is the plan's recordkeeper, which is where participants log in to see their balance.
I no longer work at Biogen Inc. How do I access my 401(k)?
Your account stays with Fidelity NetBenefits after you leave, so you can log in with the same credentials. If your balance was small, the plan may have rolled it into an IRA in your name. If you can't find it, Beagle can locate it for you.