Thomson Reuters has released a retrospective report on the key tax developments of 2013, which included a major federal tax law as well as many significant new cases, regulations, rulings and revenue procedures.

The report alerts tax professionals to important developments and also highlights many of the rates, dollar caps and other figures that changed over the course of the year.

“While most tax practitioners are aware of the many tax changes that are effective for the 2013 tax year, many taxpayers may not be,” said Tom Long, a senior tax analyst at Thomson Reuters, in a statement. “Effective in 2013, there is a higher payroll tax and a surtax on the unearned income of higher-income individuals; higher tax rates also apply to ordinary income, while at the same time limitations are imposed on the use of the personal exemption and itemized deductions. In 2013, we saw a landmark Supreme Court decision that fundamentally altered the tax treatment of same-sex married couples.”

The special report notes milestone events for the year such as:

· The American Taxpayer Relief Act of 2012 (P.L. 112-240, 1/2/2013)

· The Supreme Court’s Windsor decision, which struck down a section of the Defense of Marriage Act that required same-sex spouses to be treated as unmarried for federal law purposes

· IRS’s post-Windsor guidance that provided clarity on the practical application of the new rules

· The long-awaited and important capitalization vs. repair regulations

· The IRS’s issuance of regulations on the newly effective 0.9 percent payroll tax on wages and self-employment income and 3.8 percent surtax on net investment income.

The report is available for download at https://tax.thomsonreuters.com/2013TaxRetrospective.