On September 16, 2011, President Obama signed long-awaited legislation on patent reform, the America Invents Act (AIA), that passed both the House of Representatives and Senate by wide margins. Changes in patent law include changing the U.S. from a first-to-invent system to a first-to-file system (effective March 2013), initiating a new post-grant review procedure to challenge patent validity outside of the courts (effective September 2012), and curbing false marking litigation by limiting standing to file such litigation to the U.S. government (effective immediately). These and other changes are intended to strengthen patent rights for patent owners, and curb abusive and excessive patent litigation practices. Other changes to the U.S. patent laws and details about the AIA are reported in our recent Legal Alert.