"This report provides an overview of income tax deductions for individuals. A tax deduction reduces the amount of a tax filer's income that is subject to taxation, ultimately reducing the tax filer's tax liability. Every tax filer has the option to claim deductions when filing their income tax return. However, some tax filers and policymakers may not have detailed knowledge of tax deductions, including future changes in the requirements to claim certain deductions. In addition, tax deductions may be of interest to Congress from a budgetary perspective, as some deductions are classified as tax expenditures, and result in losses in federal revenue. This report first describes what tax deductions are, how they vary in their effects on reducing taxable income, and how they differ from other provisions (e.g., exclusions or credits). Next, it discusses the rationale for deductions as part of the tax code. The final section includes tables that summarize each individual tax deduction, under current law. This report focuses on the standard treatment of tax deductions for individuals under the individual income tax code."
CRS Report for Congress, R42872
National Agricultural Law Center: http://www.nationalaglawcenter.org/