A Practice Note discussing how the US Department of Justice (DOJ) and Federal Trade Commission (FTC) analyze the competitive effects of vertical mergers, including common theories of competitive harm and the remedies imposed. This Note discusses the 2023 Merger Guidelines, including the framework used to determine whether a vertical merger might substantially lessen competition or tend to create a monopoly. Specifically, it addresses the ways that vertical mergers can harm competition under the antitrust laws, such as foreclosure, raising rivals' costs, increased coordination by eliminating a maverick, or allowing access to competitively sensitive information, defense arguments such as the elimination of double marginalization (EDM), as well as discussing remedies assessed in vertical mergers.