Tax Basics

Understand the terms of the debate with the Principles of Sound Tax Policy and our comprehensive Tax Basics glossary, including over 70 tax policy terms and concepts.

The Principles of Sound Tax Policy

All Tax Foundation research is guided by the principles of sound tax policy—simplicity, transparency, neutrality, and stability—which should serve as touchstones for policymakers and taxpayers everywhere. Click below to learn more.

Learn More

Tax Basics Glossary

Featured Term

Corporate Income Tax

A corporate income tax (CIT) is levied by federal and state governments on business profits. Many companies are not subject to the CIT because they are taxed as pass-through businesses, with income reportable under the individual income tax.

Read More

Top Terms

Global Intangible Low Tax Income (GILTI)

Step-Up In Basis

Net Operating Loss Carryforward

Individual Income Tax

Full Expensing

Pass-Through Business Deduction (Sec. 199A Deduction)

Child Tax Credit (CTC)

Adjusted Gross Income (AGI)

After-Tax Income

Alternative Minimum Tax (AMT)


Average Tax Rate

Base Broadening

Base Erosion and Anti-Abuse Tax (BEAT)

Bonus Depreciation

Book Income

Bracket Creep

C Corporation (C corp)

Cadillac Tax

Capital Gains Tax

Carbon Tax

Child Tax Credit (CTC)

Corporate Income Tax

Cost Recovery


Direct Tax

Double Taxation

Dynamic Scoring

Earned Income Tax Credit (EITC)

Estate Tax

Excise Tax

Foreign Derived Intangible Income (FDII)

Full Expensing

GILTI: Foreign Tax, Local Impact

Global Intangible Low Tax Income (GILTI)

Going Beyond the Headlines: Understanding Corporate Taxes

Gross Receipts Tax

Head Tax

Indirect Tax

Individual Income Tax

Inflation Indexing

Inheritance Tax

International Tax Rule

Internet Sales Tax

Itemized Deduction

Marginal Tax Rate

Mark-to-Market (MTM)

Marriage Bonus

Marriage Penalty

Mortgage Interest Deduction

Net Operating Loss Carryback

Net Operating Loss Carryforward

Pass-through Business

Pass-Through Business Deduction (Sec. 199A Deduction)

Patent Box

Payroll Tax

Pigouvian Tax

Progressive Tax

Property Tax

Qualified Business Asset Investment (QBAI) Exemption

Refundable Tax Credit

Regressive Tax


S Corporation

Sales Tax

South Dakota v. Wayfair

Standard Deduction

State and Local Tax (SALT) Deduction

Static Scoring

Step-Up In Basis

Supernormal Return



Tax Base

Tax Bracket

Tax Credit

Tax Cuts and Jobs Act (TCJA)

Tax Deduction

Tax Exemption

Tax Expenditure

Tax Gap

Tax Pyramiding

Tax Reciprocity Agreement

Tax Refund

Taxable Income

Territorial Tax System

Value-Added Tax (VAT)

Wealth Tax

Who Bears the Burden of the Corporate Income Tax?


Worldwide Tax System

TaxEDU was made possible thanks to the generous support of the Stiles-Nicholson Foundation.