The Joint Committee on Taxation today released Present Law And Background Data Related to the Individual Income and Social Insurance Taxes as In Effect for 2010 and 2011 (JCX-1-10):

This document … provides a summary of the present-law Federal tax system with respect to the individual income tax and social insurance taxes, as in effect for 2010 and 2011. The changes in 2011 primarily reflect sunset provisions of the Economic Growth and Tax Relief Reconciliation Act of 2001 and the Jobs and Growth Tax Relief Reconciliation Act of 2003 as well as the expiration of provisions contained in the American Recovery and Reinvestment Tax Act of 2009.

The current Federal tax system has four main elements: (1) an income tax on individuals and corporations (which consists of both a “regular” income tax and an alternative minimum tax); (2) social insurance taxes on wages (and corresponding taxes on self-employment income); (3) estate, gift, and generation-skipping transfer taxes, and (4) excise taxes on selected goods and services. This document provides a broad overview of the first two of these elements, excluding the corporate income tax.

In addition to the expiration of temporary provisions of Federal tax law, a number of aspects of the Federal tax laws are subject to change over time. For example, some dollar amounts and income thresholds are indexed for inflation. The standard deduction and tax rate brackets are examples of amounts that are indexed for inflation. The amount of earnings subject to the Social Security tax is adjusted annually for wage growth. In general, the IRS adjusts these numbers annually and publishes the inflation-adjusted amounts in effect for a tax year prior to the beginning of that year. Where applicable, this document generally includes dollar amounts in effect for 2010 (or as estimated to be in effect for 2011) and notes whether dollar amounts are indexed for inflation.