IRS Tax Deadlines 2026 & 2027

The deadline to file your 2025 federal income tax return is April 15, 2026. You can request an automatic six-month extension, which moves the filing deadline to October 15, 2026. However, any taxes owed are still due by April 15, 2026.

Estimated tax payments for the 2026 tax year are due quarterly: Q1 on April 15, 2026, Q2 on June 15, 2026, Q3 on September 15, 2026, and Q4 on January 15, 2027.

The deadline for IRA contributions for the 2025 tax year is April 15, 2026. This applies to both Traditional and Roth IRA contributions.

Missing a quarterly due date doesn't create a separate penalty by itself — it raises the odds of an underpayment penalty under Form 2210 unless you meet a safe harbor: paying at least 90% of your current-year tax, or 100% of your prior-year tax (110% if your prior-year AGI exceeded $150,000, or $75,000 married filing separately). The shortfall accrues interest at the IRS underpayment rate — see current IRS interest rates — from the missed date until paid. Check your exposure with the estimated tax penalty calculator, then pay through the quarterly estimated tax calculator — paying late still stops the penalty from growing further.

October 15 only extends the filing deadline — it never moved the payment deadline, which stayed at April 15. If your return still isn't filed after October 15, the failure-to-file penalty (5% of unpaid tax per month, capped at 25%, $525 minimum if more than 60 days late) starts running from October 16, stacking on top of the failure-to-pay penalty (0.5%/month) and interest that have already been accruing on any unpaid balance since April 15. Estimate the total with the late filing penalty calculator, or model your scenario with the extension planner.