Reference · Tax year 2026 · US federal
Estimated Tax Safe Harbor 2026
Meet any one of these and no underpayment penalty applies, regardless of what you actually end up owing.
| Value | What it is | Source | Verified |
|---|---|---|---|
| 90% | Safe harbor: share of current-year tax | IRS | |
| 100% | Safe harbor: share of prior-year tax | IRS | |
| 110% | Safe harbor: share of prior-year tax, high income | IRS | |
| $150,000 | AGI above which the 110% safe harbor applies | IRS | |
| $75,000 | AGI threshold for the 110% safe harbor, married filing separately | IRS |
Notes
- The prior-year test uses prior-year AGI to decide whether 100% or 110% applies — not this year's.
- AGI includes W-2 wages, a spouse's income and investment income, so a freelancer with modest profit can be over the threshold.
How this page is made
Every figure above is read directly from the rules file the calculators execute — not typed into this page. If a constant changes in the engine, this table changes with it, and the two cannot disagree. The oldest verification date on this page is .
Full list of every constant the site uses: the methodology page. Run your own numbers with the estimated tax calculator.
Figures on this page are checked against the primary source cited for each one, and the calculations behind them are covered by automated tests. No credentialed tax professional has reviewed this page. Treat it as a well-sourced starting point, not as a substitute for advice on your own situation.