Ionis Pharmaceuticals (IONS) Tax Rate (2009 - 2026)

Ionis Pharmaceuticals' Tax Rate history runs 18 years deep, the most recent figure standing at 0.24% for Q1 2026.

• On a quarterly basis, Tax Rate fell 16.0% year-over-year to 0.24% in Q1 2026; TTM through Mar 2026 was 3.77%, a 632.0% decrease from a year earlier, with the FY2025 full-year figure at 3.2%, down 578.0% from the prior year.
• Tax Rate rose to 0.24% in Q1 2026 per IONS's latest filing, from 5.19% in the prior quarter.
• Across five years, Tax Rate topped out at 15.18% in Q4 2022 and bottomed at 10.09% in Q1 2023.
• The 5-year median for Tax Rate is 0.17% (2025), against an average of 0.46%.
• Across the five-year window, Tax Rate surged 1504 bps in 2022 and slumped 1321 bps in 2023, its largest moves.
• Year by year, Tax Rate stood at 15.18% in 2022, then slumped by 87 bps to 1.96% in 2023, then jumped by 297 bps to 7.81% in 2024, then slumped by 167 bps to 5.19% in 2025, then soared by 95 bps to 0.24% in 2026.
• Per Business Quant, the three latest IONS Tax Rate figures stand at 0.24% (Q1 2026), 5.19% (Q4 2025), and 0.17% (Q3 2025).