The assembly of sequence data obtained from DNA barcodes into phylogenies or NJ trees has proven highly useful in estimating relatedness among species as well as providing a framework in which hypotheses regarding the evolution of traits or species distributions may be investigated. In this chapter, we outline the process by which DNA sequence data is assembled into a phylogenetically informative matrix, and then provide details on the methods to reconstruct NJ or phylogenetic trees that employ DNA barcode data, using only barcode data or combining barcodes with other data.