AMT Methodology (2026): How We Explain Alternative Minimum Tax on TaxCalcHub
This page documents the framework we use in AMT content: AMT as a parallel calculation based on AMTI, an exemption (with potential phaseout), AMT rates, and a comparison against regular federal income tax.
High-level model
- Compute regular federal income tax using taxable income and brackets.
- Compute AMTI by starting from taxable income and applying AMT adjustments/preferences (conceptual).
- Apply the AMT exemption (subject to phaseout conceptually).
- Apply AMT rates to the remainder to compute AMT tax.
- Compare AMT tax to regular tax; AMT applies when AMT tax is higher.
Scope
- Federal-only: AMT methodology here refers to federal AMT.
- Concept-first: we focus on mechanism and decision-making context.
- Numeric thresholds: when year-specific amounts are used, they are displayed on the guide/calculator pages and updated annually.
Common trigger categories we reference
- Equity compensation timing (e.g., certain ISO exercises).
- Unusual timing differences between regular tax and AMT.
- Large one-time income events in combination with AMT adjustments.