BIIB · CIK 0000875045
BIOGEN INC. (BIIB) SEC Filings
Browse 2708 SEC filings for BIOGEN INC., covering May 21, 1996 through Jul 1, 2026, organized by filing purpose with direct links to the original EDGAR documents.
Indexed filings
2,708
Filed in the last 12 months
81
History covered
1996–2026
Latest filing
8-K
Latest important filings
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Latest annual report
10-K
Annual report · Feb 6, 2026
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10-Q
Quarterly report · Apr 29, 2026
Open original filingLatest company update
8-K
Results of operations · Jul 1, 2026
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50 filings
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| Form | Description | Period ended | Filed |
|---|---|---|---|
| 8-K | Results of operations | Jul 1, 2026 | Jul 1, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 4 | PRIMARY DOCUMENT | Jun 9, 2026 | Jun 11, 2026 |
| 8-K | CURRENT REPORT | Jun 9, 2026 | Jun 10, 2026 |
| 8-K/A Amended | CURRENT REPORT | May 14, 2026 | Jun 10, 2026 |
| SCHEDULE 13G/A Amended | SCHEDULE 13G filing | — | Jun 5, 2026 |
| SCHEDULE 13D/A Amended | SCHEDULE 13D filing | — | May 14, 2026 |
| 8-K | Material agreement; Acquisition or disposition; Financial obligation; Regulation FD disclosure | May 14, 2026 | May 14, 2026 |
| SC TO-T/A Amended | SC TO-T filing | — | May 14, 2026 |
| SC TO-T/A Amended | AMENDMENT NO. 2 | — | May 12, 2026 |
| SC TO-T/A Amended | AMENDMENT NO. 1 | — | May 6, 2026 |
| SCHEDULE 13G/A Amended | SCHEDULE 13G filing | — | May 6, 2026 |
| 4 | PRIMARY DOCUMENT | May 1, 2026 | May 5, 2026 |
| SCHEDULE 13G | SCHEDULE 13G filing | — | Apr 29, 2026 |
| 10-Q | Quarterly report | Mar 31, 2026 | Apr 29, 2026 |
| 8-K | Results of operations | Apr 29, 2026 | Apr 29, 2026 |
| ARS | ARS filing | Dec 31, 2025 | Apr 28, 2026 |
| DEFA14A | Additional proxy materials | — | Apr 28, 2026 |
Page 1 of 2
Recent filing activity
Annual filing counts derived from this company's SEC history.
2026
66 filings
2025
72 filings
2024
88 filings
2023
94 filings
2022
79 filings
2021
83 filings
2020
66 filings
2019
69 filings
Sources and methodology
How this filing index is assembled and checked.
Filing metadata comes from SEC EDGAR submissions. Categories and plain-language labels are generated deterministically from SEC form and item codes; filing content is not summarized on this page.
Index updated: 7/15/2026
For research and education only. Always review the original SEC filing before making a decision.