Biogen (BIIB) Tax Rate (2009 - 2026)

Biogen's Tax Rate history runs 18 years deep, the most recent figure standing at 15.41% for Q1 2026.

• In Q1 2026, Tax Rate fell 731.0% year-over-year to 15.41%; the TTM figure through Mar 2026 stood at 15.47% (down 11.0% YoY), while the FY2025 annual figure was 16.94%, up 257.0% from the prior year.
• Tax Rate was 15.41% for Q1 2026 at Biogen, up from 12.68% in the prior quarter.
• In the past five years, Tax Rate ranged from a high of 51.63% in Q3 2023 to a low of 8.51% in Q4 2024.
• Historically, Tax Rate has averaged 18.2% across 5 years, with a median of 15.41% in 2026.
• Biggest YoY gain for Tax Rate was 8735 bps in 2022; the steepest drop was 10044 bps in 2022.
• A 5-year view of Tax Rate shows it stood at 8.99% in 2022, then jumped by 63 bps to 14.64% in 2023, then slumped by 42 bps to 8.51% in 2024, then surged by 49 bps to 12.68% in 2025, then rose by 22 bps to 15.41% in 2026.
• The last three Tax Rate figures came in at 15.41% (Q1 2026), 12.68% (Q4 2025), and 16.29% (Q3 2025), per Business Quant data.