On December 18, 2023, the U.S. Department of Justice (DOJ) and the Federal Trade Commission (FTC) jointly issued new Merger Guidelines. The new guidelines amend, update and replace the numerous versions of merger guidelines previously issued by both agencies, including the 2010 Horizontal Merger Guidelines and the Vertical Merger Guidelines that were issued in 2020 and later withdrawn by the FTC in 2021. Below are our key takeaways, followed by some discussion of how the agencies apply the guidelines and then a deeper-dive into some industry-specific considerations.