Direct Answer
Biogen reports a single business segment in its fiscal 2025 Form 10-K, so the whole company is managed and measured as one business. That segment's revenue was $9.9 billion (up 2.2% from the prior year), and its largest cost line was selling, general and administrative expense at 25% of revenue, leaving net income of $1.3 billion.
How Does Biogen Make Money?
Since 2024, US accounting rules (ASU 2023-07) require even a single-segment company to disclose the significant expense categories its management reviews. These are the amounts Biogen tags to its one segment, as a share of that segment's revenue.
| Line | FY2025 | FY2024 | Share of revenue |
|---|---|---|---|
| Revenues | $9.9 billion | $9.7 billion | 100.0% |
| Selling, general and administrative expense | $2.4 billion | $2.4 billion | 24.6% |
| Net income | $1.3 billion | $1.6 billion | 13.1% |
What a Single Segment Does and Does Not Tell You
One reportable segment means management runs Biogen as one business; it does not mean the company sells one product. Revenue can still be spread across products, customers and countries that the filing describes in its revenue note or Item 1 without tagging them as segments. Cost lines are the company's own categories, so they compare across years within Biogen more safely than against another company, and lines that are not listed are included in other expense totals rather than missing.
Where These Numbers Come From
Every figure on this page is a value Biogen reported in the segment note and revenue disclosures of its Form 10-K filed February 6, 2026 (accession 0000875045-26-000013), read from the SEC's Financial Statement Data Sets. The prior-year column is the comparative figure from that same filing, so it reflects any restatement for a change in segments. Category names are the company's own XBRL labels, lightly reformatted for reading.
Rows that only total other rows (for example a "Products" line beside the individual products) are left out so nothing is counted twice. This page is educational and describes reported history for fiscal 2025; it is not a forecast or a recommendation.
Frequently Asked Questions
How many business segments does Biogen have?
One. In its fiscal 2025 Form 10-K, Biogen reports a single reportable segment, so its chief operating decision maker reviews the business as a whole rather than by division.
What are Biogen's biggest costs?
The segment expenses Biogen reports, largest first: selling, general and administrative expense ($2.4 billion, 25% of revenue).
How profitable is Biogen's business?
Net income was $1.3 billion in fiscal 2025, a margin of 13.1% on revenue of $9.9 billion.